Agricultural sample processing and analysis systems and related methods

Abstract

The present application relates to an agricultural sample processing-analysis system comprising an analysis device comprising at least one mixing pump, a plasma torch device and a spectrometer. A mixing pump includes a deformable diaphragm coupled to a pumping chamber formed within a pump body. An injection pump operates the diaphragm and is integrated directly into the pump body within the internal pump bore. When actuated, the injection pump displaces the pilot fluid, which deforms the diaphragm to pump a process fluid, such as a sample fluid, to a plasma torch where the process fluid is excited to form a plasma. A spectrometer captures spectral data from the plasma and quantifies the concentration of an analyte of agricultural interest, such as a plant nutrient, in the sample fluid. Other mixing pumps for processing the sample fluid and calibrating the spectrometer may be physically and fluidly coupled together in the form of a flow network to collectively form a self-supporting housing.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to the following U.S. provisional applications filed on September 29, 2023: 63 / 586486; 63 / 586489; 63 / 586497; 63 / 586500; 63 / 586504; 63 / 586510; 63 / 586529; 63 / 586545; 63 / 586551; and others. The entire contents of the following applications are incorporated herein by reference: 63 / 586555; 63 / 586562 filed on 29 September 2023; 63 / 586514 filed on 29 September 2023; 63 / 586524 filed on 29 September 2023; 63 / 559312 filed on 29 February 2024; 63 / 646070 filed on 13 May 2024; 63 / 675847 filed on 26 July 2024; 63 / 675852 filed on 26 July 2024; 63 / 675860 filed on 26 July 2024; and 63 / 675868 filed on 26 July 2024. Background Technology

[0003] This invention relates generally to agricultural sampling and analysis, and more particularly to an agricultural sample processing and analysis system that uses plasma discharge spectroscopy to analyze soil and other types of agricultural-related samples.

[0004] Periodic soil testing is an important aspect of agricultural technology. Test results provide valuable information about soil chemical composition (such as plant-available nutrients) and other important properties (e.g., levels of nitrogen, magnesium, phosphorus, potassium, pH, etc.), enabling the addition of various soil amendments to maximize crop production quality and yield.

[0005] In some existing soil sampling processes, collected samples are dried, ground, moistened, and subsequently filtered to obtain a soil slurry suitable for analysis. An extractant is added to the slurry to extract various plant-available nutrients (analytes). The slurry is then analyzed to determine the levels of these plant-available nutrients, allowing for soil amendments if necessary to replenish depleted nutrients in certain areas of agricultural fields.

[0006] The aim is to improve the handling and analysis of any type of agricultural sample, including but not limited to soil, vegetation, fertilizer, dairy products, and other substances. Summary of the Invention

[0007] This invention provides an agricultural sample processing and analysis system configured to quantify the levels of plant-available nutrients (analytes of interest) or other parameters, wherein the ultimate goal is to optimize plant growth and crop yield by adding appropriate amounts of soil conditioners to the field based on information generated by the agricultural sample processing and analysis system. In one embodiment, the agricultural sample processing and analysis system can be partially or fully automated using a programmable logic controller (PLC) that controls the operation of the sample processing and analysis equipment.

[0008] This agricultural sample processing and analysis system receives and further processes agricultural sample fluids generated from collected agricultural samples. This system can be used to analyze a variety of agricultural sample materials and substances inherently belonging to the agricultural domain, including but not limited to, soil, vegetation, fertilizers, dairy products, or any other sample material of agricultural interest. In cases where sample materials may have been solid under their original conditions at the time of collection (e.g., soil, fertilizers, crop residues, etc.), the material can first be reduced in size by grinding or other means, and then mixed with water to form a sample slurry for processing and analysis within the agricultural sample processing and analysis system disclosed herein. In one embodiment described herein as a non-limiting example for convenience of description, the sample material may be soil; it is understood that any type of agricultural sample material that can be reduced to a liquid fluid can be processed and analyzed within this system.

[0009] One embodiment of the agricultural sample processing and analysis system includes an agricultural sample analysis device configured to further process and analyze agricultural sample fluids via plasma glow discharge spectroscopy to determine the levels of analytes of agricultural interest in the agricultural sample fluids. This information allows for the determination of the type and amount of soil conditioner needed to regulate the levels of plant-available nutrients in different parts of a farmland.

[0010] The agricultural sample analysis apparatus may include a cluster of hybrid pumps configured to pump various process fluids used in the analysis of agricultural sample fluids. In a preferred, but non-limiting, embodiment, these pumps are assembled together and physically abutted to form a housing on which the plasma torch and spectrometer of the agricultural sample processing and analysis system can be mounted and supported, thus forming a structurally self-supporting and self-contained single housing, thereby creating a complete sample processing and analysis unit that is easy to transport. The tight physical connection of the pumps is crucial for minimizing the volume of various process fluids (e.g., agricultural sample fluids containing analytes, standard solutions, diluents, etc.) contained in the internal flow network integrally formed within the agricultural sample analysis apparatus. The proportions of the various process fluids mixed and subsequently supplied to the plasma torch to generate plasma for spectrometer analysis need to be precisely controlled to maintain accurate measurements of the analyte levels present in the sample fluids.

[0011] In one embodiment, the mixing pump can be a diaphragm pump that integrates a pilot fluid actuation system directly into the pump body as an integral part thereof. This pilot fluid actuation system can include a positive displacement pump (hence the term "mixing pump") directly integrated into and mounted on the pump body, such as a syringe pump. The syringe pump is in fluid communication with a pumping chamber formed in the pump body, above which the diaphragm is positioned. The diaphragm has a pilot side facing the pumping chamber and a corresponding working side facing a corresponding pump manifold block that defines a flow path connected to a flow net. The syringe pump operatively moves a relatively incompressible, preferably liquid, pilot fluid to act on the pilot side, causing deformation of the diaphragm and thus generating a pumping action that discharges the process fluid from the working side of the diaphragm through the pump manifold block to the flow net. In the context of this agricultural sample processing and analysis system, the process fluid can be an agricultural sample fluid (e.g., soil slurry or other liquid fluid), water, a standard solution, a diluent, or other fluid used in the agricultural sample processing and analysis system. Each diaphragm pump may include an integrated pressure relief system on the pilot side of the pump to prevent overpressure in the event of blockage in the flow path downstream of the pump, as further described below.

[0012] Although this document describes a sample processing and analysis system (e.g., sample collection, preparation, and treatment) for the processing of soil samples (which represents one category of use of the disclosed embodiments), it should be understood that the same system, including the described equipment and associated processing, can also be used to process other types of agricultural-related samples, including but not limited to vegetation / plants, pasture, fertilizers, feed, dairy products, or other types of samples. Therefore, the embodiments of the invention disclosed herein should be broadly considered as an agricultural sample processing and sampling system suitable for processing any type of agricultural sample. Thus, the invention is explicitly, but not limited, to use only with the processing and analysis of soil samples for the chemical properties of interest. Attached Figure Description

[0013] The invention will be more fully understood from the detailed description and accompanying drawings, wherein like elements are similarly labeled, and in the drawings:

[0014] Figure 1 This is a high-level schematic diagram illustrating steps for generating plasma from an agricultural sample and measuring analytes of agricultural interest according to an embodiment of an agricultural sample processing and analysis system of the present disclosure.

[0015] Figure 2 It is a schematic system diagram of a programmable processor-based central processing unit (CPU) or system controller used to control the systems and devices disclosed herein;

[0016] Figure 3 It is a schematic flowchart showing a flow network formed by internal flow channels in a sample analysis device used to process agricultural samples;

[0017] Figure 4 This is a schematic diagram illustrating an exemplary arrangement of multiple flow control manifold blocks and diaphragm valves of the flow network therein;

[0018] Figure 5 This is a first perspective view of the agricultural sample analysis equipment of the system, which is operable to process and analyze flowable sample fluids;

[0019] Figure 6 This is the second perspective view of the agricultural sample analysis equipment;

[0020] Figure 7 This is the third perspective view of the agricultural sample analysis equipment;

[0021] Figure 8 This is the fourth perspective view of the agricultural sample analysis equipment;

[0022] Figure 9 This is the fifth perspective view of the agricultural sample analysis equipment;

[0023] Figure 10This is the sixth perspective view of the agricultural sample analysis equipment;

[0024] Figure 11 This is the seventh perspective view of the agricultural sample analysis equipment;

[0025] Figure 12 This is the eighth perspective view of the agricultural sample analysis equipment;

[0026] Figure 13 This is the first side elevation view of the agricultural sample analysis equipment;

[0027] Figure 14 This is the second side elevation view of the agricultural sample analysis equipment;

[0028] Figure 15 This is a rear elevation view of the agricultural sample analysis equipment;

[0029] Figure 16 This is a front elevation view of the agricultural sample analysis equipment;

[0030] Figure 17 This is a top view of the agricultural sample analysis equipment;

[0031] Figure 18 This is a bottom view of an agricultural sample analysis device;

[0032] Figure 19 This is the first vertical sectional view of the agricultural sample analysis equipment;

[0033] Figure 20 yes Figure 19 Enlarged detail image;

[0034] Figure 21 This is the second vertical sectional view of the agricultural sample analysis equipment;

[0035] Figure 22 yes Figure 21 Enlarged detail image;

[0036] Figure 23 This is a phantom perspective view of an agricultural sample analysis device, showing its internal details;

[0037] Figure 24 yes Figure 23 The enlarged detail image shows the assembly and connection of the flow control manifold block;

[0038] Figure 25 This is an exploded perspective view showing one of the multiple diaphragm-operated mixing pumps of the device, the mixing pump having an integrally integrated pilot fluid drive system that operates the diaphragm to pump process fluids.

[0039] Figure 26 yes Figure 25A cross-sectional perspective view of the pump body of a mixing pump;

[0040] Figure 27 This is a first perspective view of the sample fluid manifold block, showing its internal flow channels and diaphragm pumping chamber;

[0041] Figure 28 This is a second perspective view of the sample fluid manifold block, showing the opposite sides of the sample fluid manifold block;

[0042] Figure 29 This is a perspective view of a mixing manifold block that receives process fluid from a mixing pump;

[0043] Figure 30 This is a top perspective view of the plasma torch device of an agricultural sample analysis apparatus, which generates plasma from a sample fluid for measuring analytes of agricultural interest by a spectrometer.

[0044] Figure 31 This is the first bottom-view perspective view of the plasma torch device;

[0045] Figure 32 This is the second bottom perspective view of the plasma torch device;

[0046] Figure 33 This is a front elevation view of the plasma torch device;

[0047] Figure 34 This is a rear elevation view of the plasma torch device;

[0048] Figure 35 This is the first side elevation view of the plasma torch device;

[0049] Figure 36 This is a second side elevation view of the plasma torch device;

[0050] Figure 37 This is the first vertical sectional view of the plasma torch device;

[0051] Figure 38 This is the second vertical sectional view of the plasma torch device;

[0052] Figure 39 This is a first vertical sectional view of a second embodiment of a diaphragm-operated mixing pump, which includes a sealing system for pressure balancing of the pilot fluid drive system;

[0053] Figure 40 This is the second vertical sectional view of a diaphragm-operated mixing pump;

[0054] Figure 41 Is it possible to... Figure 5 Cross-sectional view of an air removal device used in agricultural sample analysis equipment;

[0055] Figure 42 This is a first perspective view of the air removal device;

[0056] Figure 43 This is a second perspective view of the air removal device;

[0057] Figure 44 This is a first exploded perspective view of the air removal device;

[0058] Figure 45 This is a second exploded perspective view of the air removal device;

[0059] Figure 46 This is a first side view of the air removal device;

[0060] Figure 47 This is a top view of the air removal device;

[0061] Figure 48 This is a second side view of the air removal device;

[0062] Figure 49 This is a side sectional view of the air removal device;

[0063] Figure 50 This is a first perspective view of a plasma torch device equipped with an air-operated lens cleaning system to prevent fogging on the spectrometer lenses.

[0064] Figure 51 This is a second perspective view of the plasma torch device;

[0065] Figure 52 This is a first side view of the plasma torch device;

[0066] Figure 53 This is a second side view of the plasma torch device;

[0067] Figure 54 This is a first side sectional view of the plasma torch device;

[0068] Figure 55 This is a second side sectional view of the plasma torch device;

[0069] Figure 56 yes Figure 55 The enlarged detail image shows the air hood connected to the light-collecting tube of the spectrometer;

[0070] Figure 57 yes Figure 56 Exploded view;

[0071] Figure 58 This is a top-view perspective view of the air hood of a separate lens cleaning system;

[0072] Figure 59 This is a bottom-view perspective view of the air shield;

[0073] Figure 60 This is a view from the far end of the air hood;

[0074] Figure 61 This is a close-up view of the air hood;

[0075] Figure 62 This is a first side view of the air hood;

[0076] Figure 63 This is a second side view of the air hood;

[0077] Figure 64 This is a top view of the air cover;

[0078] Figure 65 This is a bottom view of the air shield;

[0079] Figure 66 This is an axial sectional perspective view of the air shroud;

[0080] Figure 67 This is an axial side sectional view of the air shroud;

[0081] Figure 68 This is a perspective view of a plasma torch cleaning apparatus according to this disclosure;

[0082] Figure 69 This is a top view of the plasma torch cleaning equipment;

[0083] Figure 70 This is a side sectional view of the plasma torch cleaning equipment, showing the cleaning brushes of the cleaning equipment in the inactive retracted position;

[0084] Figure 71 This is a side sectional view of the plasma torch cleaning equipment, showing the cleaning brush of the cleaning equipment in the active extended position;

[0085] Figure 72 This is a top-down perspective view of the cleaning equipment;

[0086] Figure 73 This is a bottom-view perspective view of the cleaning equipment;

[0087] Figure 74 It is an exploded top-down perspective view of the cleaning equipment;

[0088] Figure 75 This is a front view of the cleaning equipment;

[0089] Figure 76 This is a rear view of the cleaning equipment;

[0090] Figure 77This is a top view of the cleaning equipment;

[0091] Figure 78 This is a bottom view of the cleaning equipment;

[0092] Figure 79 This is a top sectional view of the cleaning equipment, showing the cleaning brushes of the cleaning equipment in the inactive retracted position;

[0093] Figure 80 This is a bottom sectional view of the cleaning equipment, showing the cleaning brush of the cleaning equipment in the active extended position;

[0094] Figure 81 This is a side view of the cleaning equipment;

[0095] Figure 82 This is a side sectional view of the cleaning equipment;

[0096] Figure 83 A cleaning device is shown at an alternative mounting location on the plasma torch device;

[0097] Figure 84 This is a top perspective view of a second embodiment of the cleaning apparatus according to the present disclosure (actuator not shown).

[0098] Figure 85 This is a bottom-view perspective view of the cleaning equipment;

[0099] Figure 86 It is a top-down exploded perspective view of the cleaning equipment;

[0100] Figure 87 It is an exploded perspective view of the cleaning equipment from below;

[0101] Figure 88 This is a rear view of the cleaning equipment;

[0102] Figure 89 This is a front view of the cleaning equipment;

[0103] Figure 90 This is a top view of the cleaning equipment;

[0104] Figure 91 This is a top sectional view of the cleaning equipment, showing the cleaning brush of the cleaning equipment in the inactive retracted position;

[0105] Figure 92 This is a top sectional view of the cleaning equipment, showing the cleaning brush of the cleaning equipment in the active extended position;

[0106] Figure 93 This is a side view of the cleaning equipment (actuators are shown in dashed lines).

[0107] Figure 94It is a side sectional view of the cleaning equipment; and

[0108] Figure 95 This is a top view of the plasma torch device, showing... Figures 84-94 The cleaning equipment is in a possible but not restrictive installation location;

[0109] Figure 96 First perspective view of an alternative plasma torch device;

[0110] Figure 97 for Figure 50 A second perspective view of the plasma torch device;

[0111] Figure 98 for Figure 50 Side elevation view of the plasma torch device;

[0112] Figure 99 for Figure 50 A top view of the plasma torch device;

[0113] Figure 100 for Figure 50 A third perspective view of the plasma torch device, with some components removed;

[0114] Figure 101 for Figure 54 A third perspective view of the plasma torch device, in which the main body of the plasma torch device has been removed for observation;

[0115] Figure 102 yes Figure 54 A third perspective view of the plasma torch device, in which some components have been removed to facilitate observation;

[0116] Figure 103 yes Figure 56 Side elevation view of the plasma torch device;

[0117] Figure 104 yes Figure 57 Fourth perspective view of the plasma torch device;

[0118] Figure 105 This is a first side sectional view of the plasma torch apparatus, showing the fluid discharge box inserted into the main body of the plasma torch apparatus;

[0119] Figure 106 This is a second side sectional view of the plasma torch device;

[0120] Figure 107 This is a perspective side sectional view of the plasma torch device;

[0121] Figure 108This is an enlarged partial perspective side sectional view of the plasma torch device, showing a portion of the waste discharge system;

[0122] Figure 109 It is a perspective view of a separate fluid retention chamber;

[0123] Figure 110 This is a side view of the fluid retention box;

[0124] Figure 111 This is a first exploded perspective view of the plasma torch apparatus; and

[0125] Figure 112 This is a second exploded perspective view of the plasma torch device.

[0126] All figures need not be drawn to scale. Unless otherwise expressly stated, components that are numbered and appear in one figure but appear in other figures without being numbered are the same components. Unless otherwise expressly stated, reference to the figures herein by general figure numbering shall be interpreted as a general reference to all such figures, which may appear in multiple figures with the same general numbering prefix but different letter suffixes. Detailed Implementation

[0127] This document illustrates and describes the features and benefits of the invention with reference to exemplary (“Example”) embodiments. The description of exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. Therefore, this disclosure should not be limited to such exemplary embodiments that illustrate a number of possible, non-limiting combinations of features that may exist alone or in other combinations of features.

[0128] In the description of the embodiments disclosed herein, any references to orientation or direction are intended for convenience of description only and are not intended to limit the scope of this disclosure in any way. Relative terms (such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “upward,” “downward,” “top,” and “bottom”) and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the orientation as described below or shown in the figures discussed. These relative terms are merely for convenience of description and do not require the device to be configured or operated in a particular orientation. Unless explicitly stated otherwise, terms such as “attach,” “connect,” “link,” “interconnect,” and similar words refer to a relationship in which structures are directly fixed or attached to each other or indirectly fixed or attached to each other through intervening structures, and both movable attachment or relationship and rigid attachment or relationship.

[0129] As used throughout this document, any range disclosed herein is used as a shorthand to describe each value within that range. Any value within that range may be chosen as a boundary point of that range. Furthermore, all references cited herein are incorporated herein in their entirety. In the event of any conflict between the definitions in this disclosure and the definitions in the cited references, this disclosure shall prevail.

[0130] The processing described below and implemented by the equipment of the agricultural sample processing and analysis system shown in the accompanying drawings can be automatically controlled and executed by a programmable system controller 2820. This controller can be a main control system (such as those further described herein and...). Figure 2 As shown in the diagram. The system controller 2820 is operatively coupled to components (e.g., pumps, valves, plasma torch devices, spectrometers, etc.) of the chemical analysis subsystem 3003 disclosed herein for controlling the processing sequence and flow of fluids (e.g., water, air, slurry, extractant, standard solution, etc.) in the chemical analysis subsystem to adequately process and analyze soil or other types of agricultural samples.

[0131] Figure 1-49 Various aspects and features of one embodiment of an agricultural sample analysis apparatus 100 of the sample processing and analysis system disclosed herein are illustrated. The agricultural sample analysis apparatus receives a sample fluid for analysis, which in one non-limiting embodiment may be, but is not limited to, a prepared sample slurry comprising a mixture of agricultural solids and water. In one embodiment, the agricultural sample analysis apparatus may be configured and operable to add an extractant to the sample fluid to extract an analyte of agricultural interest (e.g., plant-available nutrients or other substances), mix the extractant and sample fluid, and then analyze the sample fluid-extractant mixture in a single self-supporting unit via plasma glow discharge spectroscopy.

[0132] The sample fluid can be any fluid originating from an agriculturally relevant source (examples of which will be described elsewhere in this document), and the sample fluid contains analytes of agricultural interest and value to be measured. Examples of sample fluids discussed herein can involve sample slurries formed from a mixture of water and agricultural solid samples, such as soil. However, the systems and apparatus described herein are not limited to use with slurries, which represent only one type of sample fluid that can be processed and analyzed.

[0133] An agricultural sample analysis apparatus 100 in one embodiment typically includes a spectrometer 300, a plasma torch 200, and a fluid manipulation system comprising a fluid interconnected flow network 101 formed by a plurality of flow channels 102 fluidly connecting pumps and valves, for controlling and guiding the flow of sample fluids (e.g., slurries or others), calibration standards (liquid solutions for calibrating the spectrometer), water for cleaning pump chambers between sample fluid analysis runs, and diluent.

[0134] In one embodiment, a diaphragm-operated mixing pump assembly may be provided, comprising a diluent pump M1, a standard pump M2, a mixing pump M3, and a sample pump M4. As further described herein, the pumps and associated valves are fluidly connected to... Figure 3 The mobile network 101 shown is illustrated.

[0135] Diluent pump M1 is operable to pump a diluent (e.g., nitric acid or other diluent) to plasma torch apparatus 200 for use in conjunction with measurements of analytes in sample fluids, such as slurries. Standard pump M2 is operable to pump a standard solution containing a known concentration of the analyte of interest to plasma torch apparatus 200 for use during spectrometer calibration. Mixing pump M3 is operable in reciprocating flow exchange with sample pump M4 for mixing sample slurry with extractant and additional water (if desired), as further described herein. Sample pump M4 is operable to pump agricultural sample slurry mixtures (including extractant and any additional diluent water) to plasma torch apparatus 200. Sample slurry can be passed through a filter located upstream of sample pump M4 (which in turn is upstream of the plasma torch), said filter being any of the filters for slurry particle size determination disclosed in the commonly owned patent application publications cited herein.

[0136] In one embodiment, each of the included diaphragm pumps M1-M4 may be a pilot fluid-actuated diaphragm pump operable to pump a desired fluid, such as agricultural sample slurry, water, a standard (standard solution), a diluent, or other fluid. Each pump includes a pump body 110. In one embodiment, the pump body may have an integral structure as shown and be formed of a suitable material, which in some embodiments may be metal or plastic. These pumps may be similar or identical in construction, differing only in the purpose and location of the fluid inlet and outlet of each pump. The pump body includes a top 105, a bottom 106, and a plurality of intersecting side surfaces 107 extending along a pump axis PA between the top and bottom. In one embodiment, the pump body 110 may be formed from a solid block of material, such as a suitable metal or preferably plastic. The various internal structures of the pump body described herein can be formed as negative features (i.e., openings), which are integrally formed into the pump body by suitable manufacturing and machining methods (such as, but not limited to, casting, molding, 3D printing, boring, etc., several methods are listed depending on the type of material selected).

[0137] Pumps M1-M4 each include a recessed pumping chamber 112 formed on one of the outer surfaces 107 of the pump body and referred herein to as the active outer surface 107a associated with the actual diaphragm action pumping mechanism of the pump (see, for example...). Figure 25 (The pump is designed for disassembly). The pumping chamber 112 includes an outwardly open cavity formed on the active outer surface 107a. An elastically deformable diaphragm 111, formed of a suitable elastomer or rubber material, is disposed at and above the pumping chamber 112, and provides a fluid seal to the pumping chamber on its inward-facing (i.e., pilot side). The opposing outward-facing sides of the diaphragm 111 constitute the working side, which is in direct wetting contact with a process fluid, such as a slurry, standard solution, diluent, water, or other fluid, depending on the pump involved. In one embodiment, the diaphragm 111 may be generally disc-shaped, having a circular or elliptical configuration. A plurality of anti-jamming grooves 113 may be recessed into the arcuate curved bottom wall 114 of the pumping chamber to prevent the diaphragm from adhering to and getting stuck on the surface during the filling stroke of the pumping chamber as the diaphragm is actuated and deformed. Any suitable configuration of anti-jamming grooves 113 may be provided, including an array of cross grooves as shown in one embodiment. During testing, it was found that if a smooth surface was provided within pumping chamber 112, the flexible diaphragm would sometimes become stuck on the concave surface. This unfortunately impedes fluid flow and pumping before the diaphragm can fully displace / deform, and prevents the proper volume of liquid in the lower chamber from being completely discharged. This results in inconsistent fluid volumes pumped with each actuation, which adversely affects proper sample fluid handling and analysis, as the volume capacity of each pumping chamber is precisely predetermined, and the timing of sample fluid discharge into the plasma torch is crucial.

[0138] It is worth noting that the concave pumping chamber 112 defines the volumetric capacity allocated by each diaphragm pump for each pump stroke. When pumps M1-M4 are actuated, the flow rate of the pumped process fluid is allocated based on the volumetric capacity of the pumping chamber. For mixing pumps, the allocated volume can vary steplessly within the maximum volume range of the pumping chamber based on the amount of pilot fluid displaced during the pump stroke.

[0139] Each of the diaphragm-operated mixing pumps M1-M4 includes a pilot fluid operating mechanism operable to allow pilot fluid flow and displacement, which actuates the diaphragm 111 to draw process fluid into the pump and pump the fluid out. In one embodiment, a positive displacement pump operable to pump the pilot fluid and actuate the diaphragm can be directly integrated into the pump body to provide the operating mechanism. This differs from the use of external pumps or pressurized air sources, which could increase the size of the equipment and system. Integrating the positive displacement pump directly into the pump body is both efficient and space-saving.

[0140] In one embodiment, the positive displacement pump can be an injection pump 115, and the pilot fluid can be a liquid such as oil or water; both are generally incompressible relative to air or other gases. In a preferred but non-limiting embodiment, hydraulic oil can be used as the pilot fluid because the elastomeric or rubber material used to manufacture the pump diaphragm is not completely impermeable to gases including air. Therefore, if air is used as the pilot fluid for actuating the diaphragm valve, some air may pass through the diaphragm from the pilot fluid side and form air bubbles in the process fluid (e.g., slurry, standard solution, diluent, etc.) on the opposite process fluid side of the diaphragm. Due to the viscous nature of oil, it is unlikely to permeate the diaphragm, or at least the permeation is minimal, which would not interfere with the analysis of the slurry by spectrometer 300. Furthermore, liquid fluids such as oil are relatively incompressible, making them more preferable as pilot fluids than air. However, it is worth noting that in some embodiments, although not preferred, air may still be used as the pilot fluid.

[0141] Each syringe pump 115 may include an elongated pump orifice 116 integrally formed in the pump body 110. This pump orifice contains a reservoir or a quantity of pilot fluid and is fluidly coupled to the pumping chamber 112 on the inward-facing pilot side of the diaphragm 111 via a crossflow channel 122a. The syringe pump 115 also includes a pump piston 117 slidably disposed within the pump orifice 116 and coupled to an operating lever 118 of a linear actuator 119. As shown, in some embodiments, the actuator 119 may be electrically powered; however, in other embodiments, a pneumatic actuator may be used. Any suitable commercially available linear actuator may be used. In one embodiment, an electrically powered linear actuator 127 with a stepper motor may be used. The stepper motor may be disposed externally at the top or bottom of the pump body 110 and closed by a cover 120, which in one embodiment is coupled to the pump body by a threaded fastener 121 or by other coupling device.

[0142] Actuator 119 can be operated alternately to extend or retract the operating lever 118 and piston 117 in the pump orifice 116. Specifically, in one embodiment, the actuator is operable to: move piston 117 in a first direction to allow pilot fluid to flow into the pumping chamber 112 of pumps M1-M4, which deforms diaphragm 111 and moves it toward the process fluid side of the diaphragm to pump process fluid; and move piston in the opposite second direction to withdraw pilot fluid from the pumping chamber, which moves the diaphragm away from the process fluid side, which can draw process fluid into the pumping chamber.

[0143] In one embodiment, the pilot fluid actuation system for diaphragm pumps M1-M4 may include a pressure relief device 128 comprising a spring-biased piston mechanism also directly integrated into the pump body 110 to save space. The pressure relief device 128 includes an elongated pressure relief orifice 122 formed directly on the pump body. In some embodiments, the pressure relief orifice 122 may be parallel to a pump orifice 116, and both the pressure relief orifice 122 and the pump orifice 116 may be cylindrical. The pressure relief orifice is connected via a crossflow channel 122a (e.g., see...). Figure 22The pilot fluid is fluidly connected to the pump orifice, allowing overpressurized pilot fluid to enter the pressure relief orifice from the system to prevent damage to the diaphragm pump's diaphragm. To provide this protection, a pressure relief piston 123 is slidably disposed in the pressure relief orifice and actuated by a pressure relief spring 124 within the orifice. The operating surface of the pressure relief piston 123 is directly acted upon by the pilot fluid, while the opposite side of the piston is acted upon by the spring. A threaded cap 125 can be connected to the pump body 110 at the pressure relief orifice 122 to retain the spring within the pressure relief orifice. The pressure relief piston and spring assembly work together to act as a fluid damper to suppress pressure surges in the pilot fluid system. During operation, overpressure in the pilot fluid causes the pressure relief piston 123 to move toward the pressure relief spring 124 and compress the spring to absorb excess pressure. When the overpressure condition is relieved, the spring relaxes, allowing the pressure relief piston to return to its normal operating position in the pressure relief orifice 122.

[0144] In each of the pumps M1-M4, the diaphragm and pumping chamber 112 are preferably vertically oriented, especially relative to the sample pump M4. Some air may enter the pumping system, which adversely affects pumping performance and flow. By vertically oriented the pumping chamber and diaphragm, air bubbles will accumulate at the top of the pumping chamber, where they can be removed during commissioning or maintenance. Any air at any location on the pilot fluid side will reduce the pump's total displacement and cause compressibility in the system, which is highly undesirable. In particular, to ensure the accuracy of spectral analysis of the sample fluid (e.g., a slurry in one embodiment) in the plasma torch device 200, the sample fluid outlet port 151 of the sample pump M4 (formed by the pump manifold block 134 described elsewhere herein) is preferably located in the middle of the pumping chamber, such as... Figure 27-28 As shown. This minimizes the possibility that any air bubbles that accumulate at the top of the pump chamber will be drawn into the slurry and discharged during each pumping stroke instead of remaining at the top of the pump chamber.

[0145] like Figure 26As shown, the pump orifice 116 and the pressure relief orifice 122 can be vertically oriented and elongated, and are integrally formed with the pump body 110. The crossflow channel 122a can be horizontally oriented, or in other embodiments, oriented at an angle to a horizontal reference plane. As shown, the pump orifice 116 and the pressure relief orifice 122 can be parallel to each other, or in some embodiments, angled to each other or perpendicular to each other. The pump orifice and the pressure relief orifice can include cylindrical walls that are slidably engaged with the pump piston 117 and the pressure relief piston 123, respectively. The pump orifice 116 terminates at the end opposite to the actuator 119 at a reduced-diameter conversion orifice 116a with a diameter smaller than that of the pump orifice. Similarly, the pressure relief orifice 122 terminates at the end opposite to the spring 124 at a reduced-diameter conversion orifice 122b with a diameter smaller than that of the pressure relief orifice. The reduced-diameter conversion orifice 122b can extend completely through the pump body 110 to define an externally accessible pilot fluid filling port for adding or removing pilot fluid. In this configuration, the reduced-bore orifice 122b is sealed by a removable plug 126 attached to the pump body. This removable plug provides selective access to a pilot fluid reservoir within the pump body, primarily defined by the pump orifice 116, the pressure relief orifice 122, and the crossflow channel 122a, for filling or withdrawing pilot fluid. As shown, the orifice defined by the reduced-bore orifices 116a and 122b is fluidly connected to the crossflow channel 122a, which in turn is fluidly connected to the pumping chamber 112 associated with the diaphragm 111.

[0146] In one embodiment, the pressure of the pilot fluid can be monitored by the controller 2820 via a pressure sensor 520, which is operable to measure the pressure of the pilot fluid (see, for example...). Figure 20 This information can be used for a variety of purposes, including determining whether a blockage has occurred in the flow channels downstream of pumps M1-M4 and for flow diagnosis. Sensor 520 can be operatively coupled to any convenient and accessible portion of the pilot fluid reservoir 521 (primarily defined by crossflow channel 122a, pump orifice 116, and pressure relief orifice 122, which hold the majority of the pilot fluid volume), providing a pressure measurement indicating the actual pilot fluid pressure. In one illustrated example, pressure sensor 520 can be operatively coupled to the pilot fluid via plug 126, which seals the pilot fluid-filled port defined by a reduced-bore transducer orifice 122b associated with pressure relief orifice 122 (described elsewhere herein). Pilot fluid pressure can be monitored using other connection points, including independent, discrete paths to the pilot fluid. Any commercially available pressure sensor can be used, configured to be operatively and communicatively linked to controller 2820.

[0147] As shown in the figure, in one embodiment, pumps M1-M4 can be vertically oriented, wherein pump orifice 116 and pressure relief orifice 122 are vertically elongated. In other embodiments, pumps can be positioned in other orientations, including horizontal orientation, wherein pump orifice 116 and pressure relief orifice 122 are horizontally elongated. In some embodiments, non-horizontal or unconventional tilted orientations of the pumps may also be employed. Not all pumps need to be in the same orientation, but in some embodiments shown in the figure, pumps can be in the same orientation.

[0148] Each diaphragm-operated mixing pump M1-M4 has an associated pump manifold block containing flow channels 102, which form an integral portion of a multi-branched flow network 101 with fluid interconnections configured to form Figure 3 The flow path is shown. Pump manifold blocks control the flow of process fluid into and out of the mixing pump. In one embodiment, four pump manifold blocks may be provided, forming an integral part of a pump assembly including manifold block 131 corresponding to diluent pump M1, manifold block 132 corresponding to standard pump M2, manifold block 133 corresponding to mixing pump M3, and manifold block 134 corresponding to sample pump M4. Other embodiments may have more or fewer diaphragm pumps depending on the different types of process fluids used in the sample analysis system. Pump manifold blocks 131-134 and mixing manifold block 130 (described further herein) may have a rectangular-cubic shape in one embodiment as shown, such that they can form a plane-to-plane interface with the diaphragm pump for sealing the pumping chamber, as further described herein.

[0149] In each of the pump manifold blocks 131-134, portions of the flow passage 102 form at least one fluid inlet port 150 and at least one fluid outlet port 151 that are fluidly connected to the pumping chamber 112 of the pumps M1-M4 for exchanging fluid with it. Some pump manifold blocks may have additional fluid ports. To illustrate this aspect, Figure 27 and Figure 28A pump manifold block 134 for sample pump M4 is shown as an example. Pump manifold block 134 may include three fluid ports defined by flow channels 102 of the pump manifold block, including a sample fluid inlet port 150a, a bottom fluid port 152a, and a central sample fluid outlet port 151a located anywhere between the sample fluid inlet port 150a and the bottom fluid port 152a. Each port 150a, 151a, and 152a is fluidly connected to the pumping chamber 112 of pump M4. In one embodiment, for a vertically oriented pumping chamber 112 as previously described herein, the sample fluid inlet port 150a may be a top port located in a first upper region of the pumping chamber, the bottom fluid port 152a may be a bottom port located in a second lower region of the pumping chamber, and the central sample fluid outlet port 151a may be located in a central region of the pumping chamber, defined anywhere between the sample fluid inlet port 150a and the bottom fluid port 152a. In one embodiment, as... Figure 28 As shown, the central sample fluid outlet port 151a can be positioned adjacent to the center of the pumping chamber 112.

[0150] The fluid ports of each pump manifold block (including) Figure 27-28 Ports 150a-152a of the sample pump manifold 134 shown extend completely through the pump manifold 134 from one side to the other, and each port is fluidly connected to a continuation thereof, the continuation including a corresponding flow channel 102 formed in the mixing manifold 130 that mates with these ports (see, for example, see...). Figure 29 The continuation of ports 150a-152a will be described further below. Figure 29 The flow channels are numbered 150b-152b respectively. The remaining pump manifold blocks 131-133 are formed in a manner similar to that of the fluid inlet and fluid outlet ports defined by the flow channel 102, with fluid inlet and fluid outlet ports formed in each pump manifold block for the respective pumps M1-M3.

[0151] Return to reference Figure 27-28 The sample fluid inlet port 150a is used to add agricultural sample slurry into the pumping chamber 112 of the sample pump M4. The bottom fluid port 152a of the sample pump M4 can be used for various purposes, such as... Figure 3 The system flow diagram is shown. After agricultural slurry treatment for analysis, one application of the bottom fluid port 152a is as follows: Figure 3The process flow diagram shows that flushing water from a water source (via opening valve V12) is introduced into the pumping chamber 112 of the sample pump to remove residual slurry from the pumping chamber between sample runs, thereby preventing contamination of the next batch of slurry to be treated. Since different batches of agricultural sample slurry may originate from different areas of farmland and exhibit varying concentrations / levels of plant-available nutrients, obtaining accurate nutrient levels in each area is crucial for developing soil remediation plans and avoiding cross-contamination. By changing... Figure 3 As shown in the valve position, the bottom fluid port of sample pump M4 can discharge flushing water to waste via open valve V8.

[0152] In another secondary application, the bottom fluid port 152a can also be used to add an extractant from an extractant source to the slurry in the pumping chamber 112 of the sample pump M4 for mixing with the sample slurry, thereby extracting the specific analyte of interest (i.e., plant-available nutrients). The sample fluid outlet port 151a is used to discharge the mixture of sample slurry and extractant after combination into the plasma torch device 200 for analysis via the spectrometer 300 after plasma excitation.

[0153] A pilot fluid injection pump 115 actuates the diaphragm 111 of each pump M1-M4, deforming the diaphragm to pump process fluid from the pumping chamber 112 by moving the diaphragm toward the process fluid side of the pumping chamber, or to move the diaphragm back toward the pilot fluid side of the pumping chamber, allowing the pumping chamber to be filled with process fluid. During pump operation, under normal conditions, actuating the injection pump 115 deforms the diaphragm, causing the injection pump to move the pump piston 117 in the opposite direction, either pushing the pilot fluid against the diaphragm to pump the process fluid, or drawing the pilot fluid back into the pump orifice 116 to fill the pumping chamber of the mixing pump. For example, for the sample pump M4, the diaphragm is deformable to allow agricultural sample fluid to flow into the pumping chamber 112 through the sample fluid inlet port 150a, or to pump the sample fluid out of the pumping chamber through the sample fluid outlet port 151a.

[0154] At least some of these pump manifold blocks 130-133 may also include one or more air-actuated diaphragm valves directly integrated into the pump manifold block, and these air-actuated diaphragm valves are designated V1 to V10 (inclusive). The term "integrated" here refers to the body of the pump manifold block forming the valve seat, as further described herein. The diaphragm valves control the flow of different fluids through the pump manifold block to pumps M1-M4 and from pumps M1-M4 to plasma torch 201 in different ways (e.g., see...). Figure 3 ).

[0155] In some embodiments shown, the sample pump manifold block 134 may not include any directly integrated diaphragm valves. However, the sample pump manifold block 134 may include a pair of two-port solenoid valves, which include... Figure 3 and Figure 27 The top water valve V11 and bottom water valve V12 are shown. These valves are externally physically connected to the pump manifold block and control the flow of water to both sample pump M4 and mixing pump M3 via the flow network shown. The top water valve V11 and bottom water valve V12 are fluidly connected to a pressurized (preferably filtered) water source and are normally closed to ensure active shut-off of water flowing into the flow network 101 system when undesirable. This active shut-off may not be possible with diaphragm valves that open / close due to pressure exerted on the diaphragm by the fluid flow generated by pumps M1-M4. Any suitable commercially available solenoid valve can be used, such as those available from SMC Corporation or other suppliers.

[0156] Figure 4 The relationship and layout of the airborne diaphragm valves and their respective manifold blocks 131, 132, and 133 are shown. The functions of valves V1-10 are as follows: Figure 3 and Figure 4 As shown. Specifically, the diaphragm valves include: V1 (diluent inlet valve) and V2 (diluent mixing valve) associated with manifold block 131; V3 (standard inlet valve) and V4 (standard mixing valve) associated with manifold block 132; V5 (sample inlet valve), V6 (sample outlet valve), V7 (extractant inlet valve), and V8 (waste outlet valve) associated with mixing manifold block 130; and V9 (mixing water valve) and V10 (transfer valve) associated with manifold block 133.

[0157] Each valve's resiliently deformable diaphragm 144 can be housed in a recessed valve seat 135 formed on one or more outer surfaces of pump manifold blocks 131, 132, and 133. In one embodiment, the valve diaphragm 134 and the corresponding valve seat 135 may be circular. One or more operating air manifold blocks 138 may be provided, including air duct connectors 138a fluidly connected to a pressurized operating air source 139 (e.g., see...). Figure 21In one embodiment, air manifold 138 can be detachably coupled to mixing manifold 130-134 in various ways. Air manifold 138 includes an internal air passage 138b configured to fluidly connect valves V1-V10 to operating air for actuating the valves and moving them between open and closed positions. The operating air acts on one side of valve diaphragm 144, while the opposite side is acted upon by process fluids (e.g., sample slurry, standard solution, diluent, water, etc.), the flow of which through flow mesh 101 is controlled by the valve. The valve can switch between a closed position that blocks flow through the valve and its associated flow passages and an open position that allows fluid flow.

[0158] Figure 4 Valves V5-V8 associated with and incorporated into the mixing manifold 130 are also shown, the mixing manifold comprising forming Figure 3 Multiple fluid channels 102, a portion of the flow network 101 shown. Mixing manifold block 130 (as shown) Figure 29 (Further shown) includes a main flow channel 130a, which is directly fluidly connected to a plasma torch 201 that extends into a plasma chamber 202 of the plasma torch apparatus 200, as further described herein. Figure 3 As shown, the main flow channel 130a is fluidly connected to pumps M1-M4 and flow channel 102. Specifically, the main flow channel 130a collects and receives flow from diluent pump M1, standard pump M2, and sample pump M4, and delivers these flow streams to the plasma torch. Since fluid from some of these pumps can be pumped to the main flow channel 130a simultaneously, in some embodiments the diameter of the main flow channel can be larger than the other flow channels in the mixing manifold block 130 to increase flow capacity. Due to this increased flow rate, the mixing manifold block 130 can be centrally located on the device 100, directly below the plasma torch apparatus, allowing the main flow channel 130a to be easily connected to the cathode tube 203 of the plasma torch apparatus 200, as further described below. The mixing manifold block with diaphragm valves V1-V10, described elsewhere herein, serves as the system's flow control device for receiving, discharging, and directing various fluids into, through, and out of the flow network 101. Various valve combinations are opened or closed for different system purposes to create different fluid pathways.

[0159] refer to Figure 29The upper portion of the main flow channel 130a defines a common mixing zone Z. This common mixing zone is the location in the mixing manifold block 130 where the flow channel 102, which receives fluid flows from the diluent pump M1 and the standard pump M2, is fluidly connected to the main flow channel to mix these fluid flows with a sample slurry and extractant mixture from the sample pump M4. Preferably, the common mixing zone Z is located at a distance from the anode needle 205 and the cathode tube 203 (see, for example...). Figure 38 The plasma electrode gap 209 between the two electrodes is no more than 3 inches. This is an important consideration because a larger than normal flow path must be used to accommodate solid particles in the sample slurry, thus increasing the volume of the flow channel and ultimately leading to an increase in the volume of sample that must be collected and delivered to the system. The shorter central channel 130a in the common mixing zone Z allows for the use of a smaller flow path volume to perform spectral analysis of the sample slurry.

[0160] In one embodiment, the mixing manifold block 130 can directly abut and engage with pump manifold blocks 131, 132, and 134 to form a sealed flow channel between them at the interface. Therefore, the flow channels 102 in these pump manifold blocks are fluidly connected to corresponding flow channels in the mixing manifold block 103, the corresponding flow channels serving as continuations of the flow channels in the pump manifold blocks, to form a... Figure 3 The flow network 101 is shown. The interface between the flow passages in the mixing manifold 130 and the flow passages in the pump manifolds 131, 132 and 134 may include an annular seal 137a, such as an O-ring disposed in a corresponding circular sealing recess 137b, to form a fluid-tight connection between them (see example...). Figure 22 and Figure 29 When the manifold blocks abut and connect together, the seal 137a is compressed and expanded to form a fluid-sealed liquid interconnect between the manifold blocks.

[0161] Pump manifold blocks 131-134, together with pump body 110, form a complete and fluid-sealed pump assembly for pumps M1-M4. Therefore, each pump manifold block has a flat, active outer surface 134a that abuts and engages with the associated active outer surface 107a of the pump body to enclose and seal the corresponding concave pumping cavity 112, with a diaphragm 111 trapped between them. To illustrate this as a representative example, Figure 27-28 A pump manifold block 134 associated with the pump assembly of the sample pump M4 is shown. The movable outer surface 134a of the pump manifold block 134 abuts against the movable outer surface 107a of the engaging sample pump body 110 (see, for example...). Figure 22 and Figure 25-26The movable outer surface of the pump manifold block 134 includes a pumping recess 136, the peripheral shape of which is configured to complement (in shape and size) the pumping cavity 112 of the sample pump body. In the illustrated embodiment, the pumping recess has a circular peripheral shape. This contrasts with the concave pumping cavity 112 of the pump body 110 (whose bottom wall has an arcuate curved shape, see...). Figure 22 and Figure 26 Conversely, the bottom wall of the pumping recess 136 may have a flat profile. The pumping recess 136 and the pumping cavity 112 are arranged in an opposing orientation to jointly form a complete operating pumping cavity, partially formed by the pump body and partially by the associated pump manifold block. Thus, the manifold block surrounds the pumping cavity. The arrangement of the manifold blocks associated with the remaining pumps M1, M2, and M3 is the same as that of the pumping recess, and for the sake of simplicity, no further explanation is needed for each pump.

[0162] In some embodiments, the pumping recess 136 of the pump manifold blocks 131-134 may also include anti-jamming grooves 113 similar to the pumping chamber 112 of the mixing pumps M1-M4. These anti-jamming grooves in the manifold block are recessed into the flat bottom wall of the pumping recess 136 to prevent the diaphragm from adhering to and getting stuck on the surface when the diaphragm 111 is actuated and deformed toward the manifold block during the outward pumping fluid stroke. Any suitable anti-jamming groove arrangement can be provided as needed to prevent diaphragm adhesion.

[0163] The block pump body 110, mixing manifold block 130, and pump manifold blocks 131-134 of pumps M1-M4 are all polygonal. They can be tightly abutted and detachably connected together to form a compact device housing 100a with the configuration shown in the figure. In one embodiment (for example, see...), Figure 22 These components can be joined together as shown in the figure using threaded fasteners 140. Threaded fasteners can also be used in a similar manner to detachably connect each pump manifold block to its corresponding pump. The pump body and manifold block may include fastener mounting openings (e.g., as shown in the figure). Figure 29 As shown, the fastener mounting opening allows for threaded engagement of the threaded fastener 140. In other embodiments, other mechanical coupling devices may be used instead of threaded fasteners, or in addition to threaded fasteners. The housing 110a has sufficient structural rigidity to support the plasma torch assembly 200 and the spectrometer 300, which are attached to the block component by appropriate means (such as threaded fasteners). When the flow-related block component is assembled, the housing becomes a structurally self-supporting unit, and is easy to carry and transport. Notably, the fluid-side components, plasma generation components, and spectrometer components are co-encapsulated together to form a complete agricultural sample fluid analysis system.

[0164] According to one aspect of the invention, the mixing pump M3 and the sample pump M4 are based on... Figure 3 The components are fluidly connected and operable as a mixer for combining an extractant and additional water (if desired) with an agricultural sample fluid (which may be a slurry in some embodiments). Physically, the mixing pump M3 with manifold 133 can be stacked vertically on top of the sample pump M4 with manifold 134 to facilitate mixing fluids / chemicals. As mentioned elsewhere herein, the sample pump manifold 134 includes three ports: a sample fluid inlet port 150a, a sample fluid outlet port 151a, and a bottom fluid port 152a. The mixing pump M3 is fluidly connected to the sample pump M4 via a transfer valve V10. In operation, a sample slurry is added to the sample pump M4 via the sample fluid inlet valve V5. In the sample pump, a suitable amount of extractant, formulated to extract the analyte of interest from the slurry, is added to the slurry. If necessary, additional water can be added to the mixture in sample pump M4 via electric water valve V12 to dilute the slurry to a desired water-to-solids ratio (e.g., soil / water ratio in one embodiment). Preferably, each component of the slurry mixture (i.e., slurry, extractant, and water) is added one-by-one to the pumping chamber 112 of sample pump M4, such that the amounts of each fluid added are precisely metered, allowing control over the composition of the mixture. Once mixing is complete, mixing pump M3 and sample pump M4 can be operated alternately to move the slurry mixture back and forth between the pumps to ensure thorough mixing. As an example, in Figure 3 With the transfer valve V10 open, sample pump M4 discharges the slurry mixture into mixing pump M3. Mixing pump M3 then returns the slurry mixture to sample pump M4. This process can be repeated one or more times as needed until the slurry mixture is completely mixed. No physical agitation occurs in the slurry mixture. After mixing, sample pump M4 can discharge the slurry mixture to mixing manifold block 130 via sample fluid outlet port 151a, and then to plasma torch 201 through the main flow channel 130a therein.

[0165] The plasma torch device 200 and spectrometer 300 of the agricultural sample fluid analysis system will be further described below. The plasma torch device 200 is an electrically powered device for preparing agricultural samples for spectroscopic examination, which is performed by vaporizing the agricultural sample fluid (such as slurry or other liquid) to generate plasma. Therefore, the plasma torch device 200 includes: two fluid sections fluidly connected to a pump M4 to receive the sample fluid; and an electrical section operable to excite and vaporize the sample fluid to generate plasma for analysis by the spectrometer 300.

[0166] Figures 30-38The plasma torch apparatus is shown separately and in more detail. Referring first to these figures, the plasma torch apparatus 200 generally includes a body 210, which in one embodiment may have a rectangular cuboid shape, including a top 211, a bottom 212, and four adjacent sides 213. Other housing configurations may be used, and this does not limit the invention. The configuration of the body 210 defines an open plasma chamber 202. The body 210 may be detachably coupled to and supported by one or more of the diaphragm pumps M1-M4 and / or manifold blocks 130-134. Threaded fasteners such as those described herein may be used. The body 210 may be generally rectangular cuboid in shape and may comprise an integral body formed of a suitable material (such as metal or plastic) or a combination of these or other materials.

[0167] The main body 210 of the plasma torch apparatus supports the plasma torch 201, which has a portion exposed in the plasma chamber for generating plasma from agricultural sample fluids for analysis. The housing also supports a pair of electrodes; one electrode 208 is electrically connected to a suitable power supply PS, which in one embodiment may be a DC power supply, and the other electrode 207 is electrically connected to ground G (e.g., ...). Figure 36 (Illustrative illustration). In this arrangement, electrode 208 constitutes a positive electrode, and electrode 207 constitutes a ground electrode.

[0168] The plasma torch 201 includes an anode needle 205 electrically connected to a positive electrode 208 and a cathode tube 203 electrically connected to a ground electrode 207. The anode needle 205 may have a solid structure and be supported by a needle holder 206 connected to the body 210 of the plasma torch device (see example...). Figures 37-38 A needle holder 206 defines a channel 206a in which an anode needle 205 is received at least partially. The needle holder is electrically connected to a power electrode 208, which in turn supplies power to the anode needle. A cathode tube 203 is supported by a tube holder 204, which defines a channel 204a in which a cathode tube is received at least partially. The polarities of the anode and cathode can potentially be reversed, and there are a variety of possible options, such as, but not limited to: (1) a +5kV positive electrode (anode) at the top and a grounded (0kV) solution (cathode) at the bottom; (2) a +5kV positive electrode solution at the bottom and a grounded electrode at the top; (3) a -5kV negative electrode at the top and a grounded (0kV) solution at the bottom; or (4) an AC power supply connected to the anode (±5kV) and a grounded solution (0kV). The tube holder is electrically connected to a grounding electrode 207, which in turn grounds the cathode tube. In one embodiment, the anode needle and cathode tube may each have a generally cylindrical shape and be formed of a conductive metal. Other shapes and profiles are also possible.

[0169] One end of each of the anode needle 205 and the cathode tube 203 extends a distance into the plasma chamber 202. A gap 209 is spaced between the ends of the anode needle and the cathode tube in the plasma chamber, in which plasma is generated in some embodiments by agitating a flow of agricultural sample fluid (e.g., sample slurry). To deliver the slurry into the plasma chamber, the cathode tube 203 includes a longitudinal fluid passage 203a that extends completely through the cathode tube from a flow discharge end in the plasma chamber to an opposing flow inlet end, which may be positioned within a channel 204a of the cathode tube holder 204 (e.g., see...). Figures 37-38 ).like Figure 3 As shown, cathode tube 203 is fluidly connected (fluidly communicated) with all process fluids, including sample pump M4 which receives sample slurry via the main flow channel 130a of mixing manifold block 130 (see example). Figure 29 In one embodiment, the cathode may be configured to inject a conductive fluid into its longitudinal fluid passage and mix the conductive fluid with the sample fluid upstream of the gap. Exemplary conductive fluids include nitric acid and hydrochloric acid.

[0170] In one embodiment, the body 210 of the plasma torch apparatus further includes a waste trough 215 positioned within the plasma chamber 202, the waste trough being integrally formed with the body. The housing is generally rectangular-cubic in shape and may comprise an integral body formed of a suitable material (e.g., metal or plastic). As a non-limiting example, other body shapes, such as circular (cylindrical), may also be used. The waste trough includes a recess formed in the bottom wall of the plasma chamber that collects excess process fluids discharged from the cathode tube 203, such as agricultural sample fluids (e.g., sample slurry), standard solutions, diluents, or rinsing water. The waste trough 215 extends partially from the front 216 of the body 210 toward the rear 217 of the body 210 in a front-rear direction and partially in a left-right direction in the region below the cathode tube. The waste trough may be concave and curved from one side to the other, such that waste fluids accumulate in the central portion of the trough. A waste channel 214 is formed on the bottom wall of the channel to collect waste fluid and guide it outward to a waste disposal point through an outlet opening 214a. In one embodiment, the outlet opening 214a penetrates one side of the plasma torch housing. A waste fluid connector 214b may be provided, configured to fluidly connect with a waste conduit (e.g., pipe or fitting, not shown) to transfer excess waste process fluid to the waste disposal point.

[0171] The plasma torch apparatus 210 is operatively docked and coupled to a spectrometer 300, which has a direct or indirect line of sight into the plasma chamber 202 for capturing light emitted by the plasma for analysis to measure analytes of agricultural interest in a sample slurry. A non-limiting example of an indirect line of sight is the use of an optical fiber or optical bending lens configuration to capture and direct the light emitted by the plasma to the spectrometer. A non-limiting example of a direct line of sight from the plasma chamber to the spectrometer, as shown, is the use of a linear light collector. For this example, the body 210 of the plasma torch apparatus includes a rear through-channel 220 that extends through the rear wall of the body to form and be configured to receive the light collector 301 of the spectrometer, thus providing the spectrometer with a direct line of sight into the plasma chamber 202. In one embodiment, the light collector 301 may include an objective lens 302 that forms a physical barrier preventing vapor or mist generated by the excitation of plasma in the plasma chamber 202 from reaching and wetting the operating components of the spectrometer (such as photodetectors and electronics). In some embodiments, lens 302 may be made of a suitable material, such as sapphire or quartz. Preferably, lens 302 may be located at a distance CL from the centerline of plasma torch 201 (defined by the anode and cathode, see example...). Figure 37 At a distance of 1-4 inches, in one embodiment as shown, the anode and cathode can be vertically oriented. Since the intensity of light captured by the spectrometer decreases with increasing distance, it is preferable to place the spectrometer as close as possible to the plasma, but not too close, within a preferred distance range for strong light signals, to reduce lens contamination / fogging, as described below. Figure 38 In one of the preferred embodiments, the through channel 220 may extend horizontally through the rear wall 217a of the body 210.

[0172] When a wet mixture of agricultural sample slurry is excited and vaporized in plasma chamber 202, lens 302 may fog up. This fogging can adversely affect the accuracy of measurements performed by the spectrometer. To help address this issue, lens 302 is recessed into through channel 220 and separated from plasma chamber 202 by a distance chosen to minimize vaporized slurry deposition and fogging on the lens surface. In other embodiments that may not be sufficient to solve the problem, an automated lens cleaning system can be provided to clean the lens and defog it.

[0173] In one embodiment, the lens cleaning system may include blowing an airflow onto the outer surface of the lens 302 facing the plasma chamber 202. The rear wall 217a of the plasma torch body 210 includes an air inlet channel 221 (e.g., in fluid communication with a pressurized air source 223) that is fluidly connected to the pressurized air source 223. Figure 38(Illustrative illustration). In some embodiments, the air may be heated above ambient temperature to increase the dew point of the airflow and prevent condensation and drying of any moisture that may have condensed on the lens. Air inlet channel 221 is fluidly coupled to through channel 220 and configured to guide the airflow through spectrometer lens 302. The air is captured by air outlet channel 222 in the rear wall 217a of the housing, which is fluidly coupled to a lower ambient atmospheric pressure. In one embodiment, the air may travel tangentially over the exposed lens surface to minimize the possibility of some air escaping through through channel 220 into plasma chamber 202 (which could potentially disrupt the plasma).

[0174] To further prevent the defogging airflow from disturbing and agitating the plasma generated in the plasma chamber 202, the plasma chamber can be provided with a light-transmitting barrier 220' (in... Figure 38 (Illustrated by dashed lines) is physically sealed to the spectrometer lens 302 and the airflow.

[0175] Other methods can also be used to defog the spectrometer lens 302, including but not limited to: electrically heating the lens with a heater; continuously applying a stream of cleaning solution to the lens surface; physically wiping the lens using a mechanical wiping device that includes a wiping element that contacts and moves on the lens surface, etc.

[0176] Another cleaning method involves allowing a first fluid to flow through the cathode tube 203 into the plasma chamber 202 to remove any prior fluid from previous sample runs from the cathode tube 203. The first fluid can be water (e.g., deionized water). This may result in fluid from previous sample runs depositing on the anode needle 205, which could contaminate the next sample, or excessive first fluid depositing on the anode needle 205, which could dilute the next sample. A second fluid is then allowed to flow through the cathode tube 203 to remove any material that may have deposited on the anode needle 205. The second fluid can be a gas, such as air. By removing any prior material or any first fluid from the anode needle 205, the anode needle 205 remains clean to provide more accurate results.

[0177] The spectrometer 300 can be any commercially available spectrometer suitable for use with atmospheric pressure glow discharge flowing liquid cathode atomic emission spectrometry performed by the agricultural sample analysis apparatus 100. This detection technique is well known in the art.

[0178] The following is a brief description of a method or process for operating an agricultural sample analysis device 100 to process and analyze agricultural sample fluids. The process described below, as well as other aspects of processing and analyzing sample fluids, can be automatically controlled and implemented by a programmable controller 2820, which is further described herein.

[0179] During operation, the diaphragm-operated mixing pumps M1, M2, and M4 can initially be switched on / off. Figure 3 The appropriate valves shown are respectively filled with their respective process fluids, which include diluents, standard solutions, and agricultural sample fluids. The sample fluid may be a slurry containing solids, or filtrate obtained from filtering agricultural solid slurries (e.g., soil, crop residues, fertilizers, etc.) from outside the device 100, and then added to the sample pump M4. If desired, extractant and additional water may be added to the sample pump M4 via the extractant inlet valve V7 and water valves V11 or V12 to further prepare the sample fluid for processing and analysis. As previously described herein, the mixture may be mixed by exchanging one or more cycles using the mixing pump M3 to ensure thorough mixing and produce a homogeneous sample fluid for plasma generation.

[0180] Once the diluent pump M1, standard pump M2, and sample pump M4 are started using their respective process fluids, the system is ready to begin pumping agricultural sample fluid (i.e., a mixture of sample fluid, extractant, and additional water (if added)) to the plasma torch 200 to generate plasma. Reference Figure 1 This illustrates the basic process. Before igniting the plasma, the diluent, standard solution, and agricultural sample fluid can first be pumped and delivered to the plasma torch 201 of the plasma torch apparatus 200 via the mixing manifold block 130 and its main flow channel 130a (as previously described herein). This provides a "rinse" period to remove any air bubbles that may have been entrained in the process fluids before ignition of the plasma. These three process fluids can be pumped and discharged to the plasma torch at a preselected proportional rate, which can be programmed into a controller 2820 that controls the processing sequence and analysis performed by the sample analysis device 100. Thus, the process involves varying the individual flow rate of each of the mixing pumps M1, M2, and M4 to achieve a specific ratio of each process fluid in the combined flow to the plasma torch.

[0181] As a non-limiting example of the above proportioned flow scheme, in some embodiments, a ratio of 20% sample fluid, 20% standard solution, and 60% diluent can be used. Other proportioned flow combinations can be appropriately used for different analytes. The three process fluids are mixed in the mixing zone Z of the mixing manifold block, then flow into the cathode tube 203, and from the cathode tube, the fluid is distributed into the gap G between the cathode and anode (see also...). Figures 36-38The flow to the plasma torch can be initiated before plasma is ignited to allow time for the flow to equalize. The combined process fluid flow can be delivered to the plasma torch 201 at an appropriate preselected fixed flow rate (e.g., ml / min), which can be at least partially selected to establish a stable plasma.

[0182] Based on one aspect of the use of process fluids to generate plasma from sample fluids, standard solutions, and / or diluents, the inventors have discovered that the steady-state flow rate of these process fluids, which is desired for measuring the analyte in the sample fluid, is not the ideal flow rate for generating and initially sustaining plasma. Specifically, it has been found that higher flow rates of these process fluids are advantageous for generating plasma.

[0183] Therefore, the processing or method for operating a plasma torch may include, but is not limited to, the following steps: increasing the flow of process fluid through a hollow electrode of the plasma torch to a first flow rate; exciting plasma from the process fluid by energizing the hollow electrode; reducing the flow of process fluid to a second flow rate below the first flow rate; and measuring an analyte of interest in the process fluid at the second flow rate. The first flow rate increases the amount of process fluid dispensed, which in turn reduces the effective air gap measured between the fluid and the anode or cathode (one of which is a hollow electrode configured to receive and dispense the process fluid, and the other may be a solid electrode). Once the plasma has been excited and stabilized, the flow rate and effective air gap can be reduced to a steady-state flow state at the second flow rate to collect analyte measurements. The process fluid may include a sample fluid containing an analyte of agricultural interest and value. This stepwise and phased flow rate control is effective for exciting and stabilizing the plasma generated by the energized plasma torch.

[0184] Once the flow has been established, the plasma torch 201 is energized by switching on the power supply to the plasma torch apparatus, which excites plasma between the process fluid flow and the opposing electrodes. The controller 2820 can start a timer after plasma excitation for a pre-programmed "wait time". This ensures that the plasma has stabilized to avoid inaccurate measurements of analytes of agricultural interest in the sample fluid. After the timer ends, the spectrometer 300 captures the light (spectrum) emitted by the plasma to measure the analyte. The spectrometer can perform one or more spectral capture events (exposures) to provide multiple data points, which can be averaged to determine the level or concentration of the analyte (e.g., a plant-available nutrient) present in the sample. The measurement results are transmitted and communicated to the controller 2820.

[0185] Once the measurement is complete, plasma torch 201 is de-energized, and pumps M1, M2, and M4 can be stopped. This concludes the first sample processing procedure.

[0186] While in the above non-limiting example, the plasma is generated by three process fluids and the associated spectral measurements are collected by spectrometer 300, in other embodiments, plasma and spectral measurements can be generated and performed by simply flowing the agricultural sample fluid through plasma torch 201. In other variations of this process, the diluent and sample fluid can be mixed in proportion (excluding the standard solution) to generate plasma and capture spectral data, and then a portion of the diluent can be replaced with the standard solution. For example, the initial flow to the plasma torch may include 80% diluent and 20% sample fluid to generate plasma and capture spectral data initially. The standard solution can then be enabled to replace a portion of the diluent until a ratio of 20% sample fluid, 20% standard solution, and 60% diluent is established, while maintaining plasma excitation and capturing spectral data with spectrometer 300. Other ratios of diluent, standard solution, and sample fluid can also be used.

[0187] It is noteworthy that the combined flow of the aforementioned process fluids (diluent, standard solutions containing known amounts of the analyte in the sample, and agricultural sample fluids) allows for online dynamic calibration of the spectrometer during analytical processing. In other embodiments, a typical batch calibration method can be used to calibrate the spectrometer, in which successive processes of individual standard solutions with different analyte concentrations are processed independently to generate plasma and capture spectral data. Therefore, any suitable method for calibrating the spectrometer and analyzing agricultural sample fluids is possible using this agricultural sample processing and analysis system.

[0188] This agricultural sample processing and analysis system advantageously provides good operational flexibility through the controller 2820 and internal flow network 101 shown in the sample analysis device 100 described earlier herein. In addition to generating and mixing different process fluids (e.g., diluents, standard solutions, and agricultural sample fluids) from mixing pumps M1, M2, and M4 as described earlier herein, the system can also achieve a gradual decrease in the flow rate of the first process fluid flowing from the first mixing pump to the plasma torch 201, while simultaneously a gradual increase in the flow rate of the second process fluid discharged from the second mixing pump to the plasma torch, to maintain a minimum flow rate to the plasma torch, which is necessary for maintaining a stable plasma. Furthermore, the first mixing pump can be filled with the first process fluid while simultaneously discharging the second process fluid from the second mixing pump to the plasma torch. The operation of the first and second mixing pumps can be switched back and forth, thereby maintaining a continuous supply of either the first or second process fluid to the plasma torch to maintain a stable plasma. These are some non-limiting examples of the operational flexibility of the system. Because the system's flow network 101 includes... Figure 3 The mixing pump and valves shown are therefore subject to other variations.

[0189] The agricultural sample processing and analysis system also includes the setup for flushing and cleaning the mixing pump M3, the mixing sample pump M4, and the plasma torch 200 with water by opening and closing appropriate valves associated with the water source and pumps, such as... Figure 3 As shown. Wastewater is disposed of via waste outlet valve V8. A water cleaning system can be used between each sample fluid flow through the system to prevent cross-contamination of samples.

[0190] In one embodiment, when made of plastic, a transparent polymer material can be used to form the integral manifold blocks 130-134 and the mixing pump body 110 to allow visual observation of the fluid being processed therein and the operation of the pump and diaphragm valve. Certain non-limiting examples of thermoplastic (polymer) that can be used include, but are not limited to: PMMA (polymethyl methacrylate, commonly referred to as acrylate), PC (polycarbonate), PS (polystyrene), PVC (polyvinyl chloride), CPVC (chlorinated polyvinyl chloride), etc. Examples of suitable elastomeric materials that can be used to form the diaphragms of the mixing pump and valves V1-V10 include, but are not limited to: silicone rubber, PDMS (polydimethylsiloxane), fluorosilicone rubber, neoprene rubber, etc. Compressed air used to keep the diaphragm valve closed can permeate through the elastomeric diaphragm over time, resulting in air bubbles on the process fluid side of the valve. These air bubbles negatively affect the ability to properly maintain the volume of the liquid because they displace the originally precise fluid volume being manipulated. Fluorosilicone rubber is a preferred, non-limiting material because its low permeability helps reduce the diffusion of gas through the membrane over time, thus solving the aforementioned problems.

[0191] Alternative plasma torch devices

[0192] Figure 96-112 Another plasma torch device 200' is shown. The features and general operation of the plasma torch device 200' in generating plasma are generally similar to those of the plasma torch device 200 previously described herein. The plasma torch device 200' also has a body 210' that defines a plasma chamber 202' in which the plasma torch 201' and its components, previously described herein, are housed. In this embodiment, the plasma chamber 202' has a generally circular cross-sectional shape (e.g., see...). Figures 106-107 (and 111-112), which defines an arcuate curved wall to advantageously and effectively assist in the rapid downward discharge of waste sample fluid and washing water from the curved sidewall of the plasma torch body 210' to the bottom of the chamber for treatment via a waste discharge system, as further described herein.

[0193] In one embodiment, the plasma torch body 210' may have a solid, monolithic structure, which may be formed in the form of various openings / holes and features described herein in the form of negative features via machining, casting, or other manufacturing techniques used in the art. In other embodiments, a pair of solid blocks mechanically joined together by fasteners or other suitable methods may be used instead of a single monolithic body. Suitable metallic or polymeric materials may be used to form the body. The body 210' may have a blocky configuration, such as a rectangular cube as shown; however, other body shapes may also be used. Along with the intended use of the plasma torch 200', the body 210' may be considered to have a top 200a', a bottom 200b' opposite the top, and a plurality of sides 200c' extending vertically between the top and bottom (see, for example, ...). Figure 96 ).

[0194] A blower or fan 230' is attached to the side of the plasma torch device body 210'. The blower or fan can be configured and arranged to exhaust gas (e.g., air) from inside the plasma torch device 200' (i.e., the plasma chamber 202') to provide a vacuum inside the plasma torch device 200', or alternatively to supply gas (e.g., air) to the plasma torch device 200'. The fan 230' is fluidly connected to the plasma chamber 202' via an airflow hole 265' formed through the plasma torch device body 210' (see example...). Figure 106 The directional arrow AF shown in the diagram indicates two possible airflow directions, depending on whether the fan applies positive or negative pressure (vacuum) to the plasma chamber.

[0195] In one embodiment, as shown in the figure, fan 230' can be supported and coupled to body 210' via a suitably configured mounting bracket 230d and associated threaded fastener 230e. The fan is fluidly connected to plasma chamber 202' to introduce or extract gas from the plasma chamber, depending on the fan's configuration and operation. In one embodiment, fan 230' includes a fan housing 230b, which is detachably coupled to plasma torch body 210' by suitable means commonly used in the art (e.g., fasteners, etc.). Fan housing 230b supports fan motor 230c, which is coupled to a fan impeller or blades (not shown) within the housing to extract or inject gas (e.g., air) from or into plasma chamber 202', depending on the direction of rotation of the fan blades. The fan housing also includes a fluid connector 230a, which, depending on the selected fan configuration, discharges gas from the plasma chamber or injects air into the plasma chamber. Any suitable commercially available electric fan with appropriate flow capacity can be used.

[0196] Because the sample fluid is excited via the plasma torch 201, the torch chamber has a humid and condensing environment. In the absence of airflow in the plasma chamber 202', the liquid rapidly condenses on the surface of the spectrometer 300 (e.g., photodetector) lens 302', causing a calibration shift, which continues to change as condensate accumulates and evaporates. Therefore, it is necessary to use a fan 230b to remove vapor condensation before it deposits on the lens.

[0197] It is worth noting that while high airflow promotes evaporation, it can also disrupt plasma stability, leading to unstable and inaccurate light intensity readings measured by the spectrometer. Therefore, it is advantageous to control the airflow rate based on the operational phases of the plasma torch apparatus, which include using low fan speeds and low airflow rates during plasma optical measurements and high fan speeds and high airflow rates between measurements. This can be accomplished by operating fan 230' via a variable-speed fan (i.e., a variable-speed fan motor), or alternatively by using other airflow control methods (e.g., a constant-speed fan used with position-adjustable airflow baffles, gates, etc.) to change and control the airflow rate between low and high.

[0198] In a non-limiting operating method, for example but not limited to, fan 230' can operate at a higher first airflow rate (e.g., high fan setting) when: sample fluid is pumped into the plasma chamber prior to excitation while the torch is being rinsed with water; and sample fluid is pumped into the plasma chamber after excitation during rinsing while the system waits to establish a steady-state sample fluid flow rate for plasma excitation. Once a steady-state flow rate is achieved, the fan can operate at a lower second airflow rate to excite the plasma and obtain stable readings, while spectrometer 300 collects and analyzes the light emitted from the plasma (e.g., by comparison with the spectrometer's calibration values). This yields more significant, repeatable, and stable sample fluid analysis results.

[0199] Fan 230' can provide airflow within plasma chamber 202' via positive pressure or vacuum to help reduce condensation within plasma chamber 202'. When fan 230' provides a vacuum to plasma chamber 202', fan 230' provides a single outlet airflow exiting plasma chamber 202'. This reduces the need for multiple flow paths within plasma chamber 202'. The speed of fan 230' can be controlled to provide a desired vacuum level within plasma chamber 202', thereby reducing condensation within plasma chamber 202'. Notably, a blower or fan can be provided in which the rotation direction of the fan blades can be reversed to selectively provide positive pressure airflow to the plasma chamber or evacuate the plasma chamber. This can be achieved by equipping the fan with a reversible motor and / or circuitry to selectively control the rotation direction of the fan motor shaft and, consequently, the rotation direction of the fan blades. Such a blower or fan is commercially available.

[0200] A light-collecting tube 301', coupled to one side of the plasma torch apparatus 200' (e.g., body 210'), is configured and arranged to collect light emitted by the plasma torch 201' from inside the plasma chamber 202' of the plasma torch apparatus 200'. In one embodiment, the light-collecting tube 301' may be positioned opposite the fan 230, or at any other suitable location on the plasma torch apparatus. The light-collecting tube 301' may generally be similar to the light-collecting tube 301 described earlier herein, and also includes a lens 302' that collects the light emitted by the excited plasma and transmits the light to the spectrometer 300 for analysis. As further described herein, the light-collecting tube 301' provides the spectrometer 300 with a line of sight into the plasma chamber 202' via a linear aperture 251 formed through the plasma torch apparatus body 210'.

[0201] Optionally, the heating element 231' is positioned adjacent to the light-collecting tube 301'. The heating element 231' can be electrically operated to provide resistance heating and can supply heat to the interior of the plasma torch device 200' (i.e., the plasma chamber 202') such that the temperature is above the dew point of water. The heating element 231' is preferably located near the light-collecting tube 301' to directly heat the environment (air) surrounding the lens 302' inside the plasma chamber 202' via convection heating at the inner end of the light-collecting tube. Since the light-collecting tube 310' is close to the heating element, the heating element also heats the light-collecting tube 310' via radiation heating. The heater ensures that moisture advantageously does not condense and deposit on the light-collecting tube 301', nor does it cause fogging of the lens 302' of the light-collecting tube, which would interfere with the accuracy of light capture and readings obtained by the spectrometer 300.

[0202] In a non-limiting embodiment, the heating element 231' may be part of a box heater 232', which is connected to an electric power source via wire 233'. The heating element may be generally cylindrical and formed of a suitable thermally conductive metal, inserted through the body 210' of the plasma torch assembly 200' near the light-collecting lens 302'. Due to the high humidity (90-100% RH) inside the torch, the dew point is very close to the air temperature. Any surface inside the plasma chamber 202' with a temperature below the air dew point will promote condensation on that surface. Condensation on the lens can be prevented by selectively heating the lens assembly and the adjacent ambient air inside the chamber to temperatures well above the dew point (e.g., 40-60°C).

[0203] The plasma torch 201' of the plasma torch apparatus 200' includes an anode needle 205' connected to the positive electrode 208' and a cathode tube 203' connected to the ground electrode 207'. The plasma torch 201' and its operation can be generally similar to the plasma torch 201 previously described herein. Therefore, for the sake of brevity, similar components will not be described in detail here.

[0204] The cathode tube 203' includes a longitudinal fluid passage 203a' for introducing sample fluid into the plasma chamber 202' to generate plasma. The anode needle 205' may have a cylindrical solid structure and be supported by a needle holder 206' connected to the plasma torch body 210'. The ground electrode 207' is electrically connected to a grounding connector 237', and the positive electrode 208' is electrically connected to a positive electrode connector 238'. The position of the ground electrode 207' is adjustable up and down relative to the plasma torch body 210' and maintains electrical contact with the grounding connector 237', which includes a spring-biased contact rod 237a' (see, for example...). Figure 106 The position of the positive electrode 208' can be adjusted up and down relative to the plasma torch body 210' and maintain electrical contact with the positive electrode connector 238', which includes a spring-biased contact rod 238a'. The grounding connector 237' and the positive electrode connector 238' can be connected to an electrical system including a power supply (not shown). The cathode tube 203' is supported by the grounding electrode 207'. Both the anode needle 205' and the cathode tube 203' can be formed of a suitable conductive metal.

[0205] In one non-limiting embodiment, the positive electrode 208' may be movably adjustable within and relative to the plasma torch body 210' to adjust the electrode gap 209'. This allows a user to optimize the spacing between the anode needle 205' and the cathode tube 203' coupled to the electrode 208' to excite and sustain plasma, as described below. Conversely, the cathode tube 203' and its corresponding ground electrode 207' may be fixedly coupled to the body 201' and not adjustable. It is not necessary for both the cathode tube and the anode needle to be adjustable to adjust the electrode gap 209'. In other embodiments, the anode needle may be fixed, while the cathode tube may be adjustable to adjust the gap.

[0206] In one embodiment, the positive electrode 208' may be generally cylindrical in shape and threadedly engaged with the plasma torch body 210', thereby allowing the positive electrode and the anode needle 205' connected thereto to be movably adjustable relative to the body 210'. A thread 323 formed on the positive electrode 208' threadedly engages with a partially threaded through-hole 320 formed in the wall of the body 210'. The through-hole 320 communicates with the plasma chamber 202'. In operation, rotation of the positive electrode 208' in opposite directions translates into corresponding opposite linear movements of the positive electrode and anode needle 205' relative to the body 210' and toward or away from the plasma chamber 202'. In some embodiments (not shown), the positive electrode 208' can be manually rotated and threadedly adjusted with a tool to adjust the electrode gap 209'. In a non-limiting embodiment, for example, the externally accessible portion of the positive electrode 208' includes a hexagonal tool hole 321, which can be engaged by a hexagonal wrench or pliers (not shown) to rotate and linearly adjust the positive electrode. In addition to or instead of the hexagonal tool hole, the accessible portion of the positive electrode 208' may also include textured gripping features 322, such as multiple splines (as shown), knurling, or other features, to facilitate a user's gripping of the positive electrode like a knob, thereby adjusting the electrode gap 209'. The through-hole 320 in the plasma torch body 210' may include an enlarged outer portion to provide additional clearance for the user to grip the gripping features 322 and rotate the positive electrode 208'. The positive electrode 208' is fluid-sealed in the through-hole 320 via an O-ring seal 208a'.

[0207] The voltage required for plasma excitation is related to the electrode spacing (electrode gap 209'). Larger spacing requires higher excitation voltage. For example, a 2 mm gap requires an instantaneous application of 5000 V for excitation, followed by a 600 V voltage to sustain it. In one embodiment, the electrode gap 209' can be between 1.6 mm and 2.2 mm. During the setup of the plasma torch apparatus 200', a shim (not shown) of known thickness can be inserted between the cathode tube 203' and the anode needle 205', and the electrode gap 209' is set by adjusting the positive electrode 208' as described above until the shim is sandwiched between the positive electrode 208' and the ground electrode 207'. The shim can then be removed before plasma torch operation.

[0208] In one embodiment, the ground electrode 207' supporting the cathode tube 203' can be detachably coupled and inserted into the through-hole 325 of the plasma torch body 210' for mounting via a slip-in friction fit connection created by an O-ring seal 207a' on the ground electrode body. This holds the ground electrode 207' to the plasma torch body 210' in a fixed manner. The O-ring seal 207a' also fluid-tightens the ground electrode 207' in the through-hole 325 to prevent fluid leakage from the plasma chamber 202', as the ground electrode defines the chamber bottom B where waste streams from sample fluid or chamber flushing fluid (e.g., water or other liquids) accumulate. In use, variations in the ends of the anode needle 205' and the cathode tube 203' can alter the spacing in the electrode gap 209', which then requires recalibration and adjustment of the gap via the positive electrode 208' as described elsewhere herein.

[0209] The positive electrode 208' also includes a deflector 239' disposed at the base of the anode needle 205', where the anode needle is connected to the bottom of the positive electrode. The deflector 239' helps to deflect vaporized sample fluid splashes downwards back into the plasma chamber 202' when plasma is excited at the plasma torch 201' and reduces splashing onto the light collector tube 301' and its lens 302'. Therefore, the diameter of the deflector 239' is preferably much larger than the diameter of the anode needle 208' (e.g., twice or more) to effectively capture and deflect the splashes (see, for example...). Figure 106The deflector can have any suitable shape, including flat or curved deflection surfaces. In a non-limiting embodiment, the deflector 239' may include a concave surface (facing into the plasma chamber 202') defining an umbrella-shaped or parabolic shape to better collect and redirect splashes of the sample fluid downward toward the bottom of the plasma chamber 202'. The deflector 239' may also help contain the sample fluid ejected from the cathode tube 203' before the plasma is ignited and prevent the sample fluid ejected from the cathode tube 203' from flowing toward the anode needle 205', thereby avoiding splashing onto unintended surfaces of the plasma torch assembly 200' within the plasma chamber 202', and thus preventing any conductive fluid (e.g., nitric acid or other fluids) from forming an arc path (i.e., preventing arc bridging) within the plasma chamber 202' that is not located between the anode needle 205' and the cathode tube 203'.

[0210] In some embodiments, the plasma torch apparatus 200' may include a fluid retention section 240' to drain any fluids (such as residual sample fluid, rinsing / washing water, etc.) accumulated in the plasma chamber 202'. Without a fluid retention section (which functions similarly to a retention section in a typical household sink drain pipe), fluids such as water and / or air may flow back from the liquid discharge system into the plasma chamber 202' housing the plasma torch assembly. This is highly undesirable because such backflow can cause numerous problems that adversely affect the operation of the plasma torch apparatus 200'. As examples, but not limited to, liquid drawn back into the plasma chamber from the discharge system may splash and contaminate surfaces within the chamber after the previous run, potentially compromising the integrity of analyzing the next new sample fluid after the chamber has been previously rinsed. If the plasma is excited, the backflow of liquid and / or air from the discharge system can disrupt plasma stability, and unwanted liquid and / or air from a moisture-rich discharge system can increase humidity within the plasma chamber, thereby increasing the likelihood of spectrometer lens fogging.

[0211] refer to Figures 57-60 In one embodiment, the fluid retention section 240' may be in the form of a separate fluid retention box removably insertable into the plasma torch device body 210'. The fluid retention section 240' includes an elongated hollow tubular body 261' that is generally cylindrical. In one embodiment, the fluid retention section 240' may be inserted into a mounting through-hole 244' formed on the body 210' of the plasma torch device 200', which is in fluid communication with the plasma chamber 202' via a discharge crossflow conduit 248'.

[0212] The fluid retention section 240' typically includes a waste inlet 241', a waste outlet 242', and a central flow passage 247' in fluid communication with the waste inlet and waste outlet. In such cases... Figure 105 In the preferred embodiment shown, the central flow passage 247' extends linearly from the upper end 247a' of the fluid reservoir toward the lower end 247b', but does not penetrate the lower end. When the reservoir is located within the reservoir mounting through-hole 244' of the plasma torch body 210', a waste inlet 241' is disposed inside the upper portion of the reservoir mounting through-hole. Both the waste inlet 241' and the waste outlet 242' extend laterally completely through the body 261' of the fluid reservoir 240' and intersect the central flow passage 247' perpendicularly. This defines two openings for the waste inlet leading to the central flow passage and two openings for the waste outlet exiting the central flow passage.

[0213] The upper portion of the defined waste inlet 241' of the fluid retention section body has a smaller reduced diameter compared to the lower portion of the defined waste outlet 242' and the circumferentially extending annular sealing groove 266'. This forms an annular chamber 249' surrounding the upper portion of the fluid retention section and the waste inlet 241', which is in fluid communication with the crossflow conduit 248', such that fluid discharged from the plasma chamber 202' flows to and enters this annular chamber before entering the waste inlet of the retention section. Compared to the upper portion of the fluid retention section body, the lower portion of the defined waste outlet 242' of this body includes a portion with a diameter slightly smaller than that of the retention section mounting through-hole 244', such that the lower end 247b of the retention section substantially isolates the retention section mounting through-hole from the external environment, as shown in the figure.

[0214] A fluid reservoir 240' is fluid-sealed in a reservoir mounting bore 244' via one or more O-ring seals 245'. In one embodiment, a pair of O-ring seals may be provided to form a seal between the reservoir mounting bore 244' and the lower portion of the larger diameter of the fluid reservoir body 261'. The fluid reservoir body 261' includes two enlarged diameter sealing rings 267', each of which defines a circumferentially extending sealing groove 266' that retains an O-ring seal. A waste outlet 242' and a circumferentially extending annular outlet channel 260' are provided between the O-ring seals 245' and the sealing rings 267', the circumferentially extending annular outlet channel extending circumferentially around the reservoir body at the waste outlet 242'. Figure 105As best shown, the retention body 261' defines a smaller diameter reduction portion between the sealing rings 267' to define an outlet flow path, on which an O-ring seal is mounted. A waste outlet 242' and an outlet flow path 260' are located between these seals, providing a fluid seal at each end of the outlet flow path to prevent leakage of discharged fluid leaving the fluid retention section. The outlet flow path 260' intersects the inner end of a discharge port 262' formed from the outside through the plasma torch body 210'. The outer end of the discharge port 262' terminates at a discharge connector 246' connected to the body 210' of the plasma torch 200'. The discharge connector 246' is further configured to connect to a suitable discharge conduit 243', such as a flexible or rigid pipe or conduit. The discharge connector 246' conveys the waste fluid captured by the fluid retention section 240' from the plasma chamber 202' to the waste point. It should be noted that the fluid retention section 240' and the retention section mounting through-hole 244' are vertically oriented; however, the discharge connector 246', the cross-flow conduit 248' and the discharge port 262' may be vertically oriented relative to the retention section mounting through-hole 244' and are generally arranged horizontally.

[0215] An important aspect of the fluid retention section 240' is that its waste inlet 241' is located on the main body of the retention section and is a distance above the bottom B of the plasma chamber 202' defined by the plasma torch device body 210'. This allows some fluid to accumulate to a certain level or depth in the lower reservoir 215' of the plasma chamber 202', thus functioning as a fluid retention section as described above. Specifically, maintaining a certain fluid level in the lower part of the plasma chamber 202' prevents waste fluid (liquid or gas) from flowing back into the plasma chamber from the waste discharge system downstream of the fluid retention section.

[0216] refer to Figure 106The bottom B of the plasma chamber 202', defined by the top surface of the removable grounding electrode 207', is located at a first height EV1, while the waste inlet 241' of the fluid retention section is located at a higher second height EV2, as shown. Waste fluid accumulated in the plasma chamber is only allowed to be discharged through the fluid retention section 240' when the waste fluid level LV (indicated by the dashed line) in the plasma chamber reaches or exceeds the height EV2 at the waste inlet 241' of the retention section. When the plasma chamber 202' is under atmospheric pressure, the fluid levels in the plasma chamber 202' and the vertical through-hole 244' tend to be balanced as the fluid (e.g., liquid) adjusts its level automatically. If the plasma chamber is pressurized by the fan 230', the fluid in the through-hole 244' may be pushed higher than the fluid in the plasma chamber. If the plasma chamber is under vacuum, the fluid in the through-hole may be lower than the fluid in the plasma chamber. The waste outlet 242' of the fluid retention section 240' is located at a height EV3, which is lower than the height EV1 of the bottom of the plasma chamber 202', to allow waste fluid to be discharged from the plasma torch device 202' during normal operation.

[0217] With fan 230' configured and operable to create a vacuum within plasma chamber 202' (i.e., to extract air from the plasma chamber), positioning waste inlet 241' above the bottom of plasma chamber 202' allows fluid reservoir 240' to establish a waste fluid level LV of a certain depth within plasma chamber 202'. This creates an accumulation of waste fluid within plasma chamber 202' to prevent waste fluid (liquid or air) in the discharge system downstream of fluid reservoir in discharge conduit 243' from being drawn back into plasma chamber 202' by the vacuum generated by fan 230', which would lead to the problems described above and could interfere with the normal operation of the plasma torch apparatus.

[0218] Unless otherwise expressly stated, the term "fluid" is used in this disclosure in its broadest sense to cover both any type of liquid and any type of gas (e.g., air).

[0219] According to another option, the plasma torch device 200' may also be equipped with an air curtain system to protect the light-collecting tube lens 302' from contamination during plasma torch operation. This air curtain system prevents sample fluid injected from the cathode tube 203' into the plasma chamber 202' to generate plasma from being splashed onto the light-collecting tube lens 302' and contaminating it when the plasma is excited. Such contamination would otherwise adversely interfere with the spectrometer 300 acquiring accurate light emission measurements.

[0220] See in general Figures 96-98 and Figures 106-107 One or more air inlets 250 may be formed through the plasma torch body 210' to draw in drier ambient air into the humid environment of the plasma chamber 202' by operating the fan 230' in vacuum mode. In one embodiment, a pair of air inlets 250 may be provided, intersecting opposite sides of the light-transmitting aperture 251 formed through the plasma torch body 210'. In one embodiment, the air inlets 250 may intersect the light-transmitting aperture 251 perpendicularly as shown to facilitate manufacturing when drilling or otherwise opening holes in the plasma torch body 210'; however, in other embodiments, one or both air inlets may intersect the light-transmitting aperture at an angle. A light-collecting tube 301' is mounted on the body 210' of the plasma torch 200' at the outer end of the light-transmitting aperture 251, where the lens 302' of the light-collecting tube may also be positioned. The opposite inner ends of the light-transmitting aperture penetrate the plasma chamber 202'.

[0221] Air inlet 250 is in fluid communication with light-transmitting aperture 251, which in turn is in fluid communication with the plasma chamber. Therefore, light-transmitting aperture 251 intersects with plasma chamber 202' and extends from plasma chamber 202' to lens 302', which is associated with light-collecting tube 301' of the spectrometer, as previously described herein. Spectrometer 300 has a line of sight from light-transmitting aperture 251 through lens 302' into plasma chamber 202'. Lens 302' is recessed inward at the inner end of light-transmitting aperture 251 by a distance shown in the figure to further protect the lens from contamination and sputtering. In one embodiment, the cross-sections of air inlet 250 and light-transmitting aperture 251 may be circular and include elongated linear openings in length, as shown in the figure. Other cross-sectional shapes and arrangements of apertures 250 and 251 may also be used. In other embodiments, the length of air inlet 250 may also be non-linear, provided that air inlet 250 is in fluid communication with ambient air outside plasma torch body 210' and light-transmitting aperture 251.

[0222] In the operation of the air curtain system, such as when the plasma is excited, fan 230' draws air out of plasma chamber 202'. Ambient air is then drawn into light transmission aperture 251 through air inlet 250 located in front of light collector lens 302' (i.e., between the lens and the plasma chamber). Air is drawn into plasma chamber from light transmission aperture 251. The inward movement of ambient air through light transmission aperture 251 into plasma chamber 202' makes it more difficult for any splashes ejected from the excited plasma to enter light transmission aperture and reach lens 302'. Air inlet 250 also helps maintain a lower humidity level within plasma chamber 202' because drier ambient air is repeatedly drawn in and flows through the plasma chamber, resulting in frequent air exchange.

[0223] Pressure-balanced sealing system for positive displacement pumps

[0224] Figure 39 and Figure 40 Alternative embodiments of the mixing pumps M1-M4 are shown, wherein the injection pump 115, which controls the pilot fluid to operate the pumps M1-M4, also includes a pressure-balanced sealing system.

[0225] When the mixing pump is actuated, the dynamic seal formed by the slidable reciprocating movement of a pump piston 117 within the pump orifice 116 of the injection pump 115 is extremely difficult to achieve when a vacuum state occurs in the pilot fluid (e.g., oil in one embodiment). This vacuum state occurs during the return or reverse stroke, when the injection pump retracts in the pump orifice 116 to pull back the pilot fluid in the pumping chamber 112, causing the diaphragm 111 of the mixing pump to press inward against the curved surface of the concave pumping chamber (see also...). Figure 19-22 and Figure 25-26 This makes it possible for air to pass both over the seals on the pump piston 117 and (via permeation) through the seals on the pump piston 117. Once air permeates into the pilot fluid system, it displaces the oil and alters the overall volume of the pilot fluid system, thus adversely affecting the normal operation of the system. To address this problem, according to this disclosure, a method such as Figures 39-40 The pressure-balanced piston device 400 is shown.

[0226] The pressure-balanced piston 400 replaces the single-pump piston 117 with a dual-piston assembly 400s, which includes a primary operating piston 401 and a secondary sealing piston 402 connected together by a smaller-diameter intermediate connecting member 403. The sealing piston 402 is coupled to the operating rod 118 of the linear actuator 127 for reciprocating the piston assembly within the pump orifice 116 as previously described herein. This piston assembly can be a monolithic body in which both the pair of pistons and the connecting member are formed as part of the monolithic body. Thus, the connecting member can be a reduced-diameter intermediate portion of the monolithic body. In other embodiments, the connecting member 403 can be a separate component coupled to and located between the pistons 401 and 402. Each piston 401, 402 includes one or more annular seals 403, such as elastomeric O-rings, to seal the sliding interface between the cylindrical piston sidewall and the cylindrical inner surface or wall of the pump orifice 116.

[0227] As shown in the figure, because the diameter of the connecting member 403 is smaller than that of the piston and the pump orifice 116, a pressure-balanced intermediate chamber 404 is formed in the pump assembly between pistons 401 and 402. Therefore, the annular intermediate chamber 404 contains a certain amount or volume of pilot fluid (e.g., oil or other fluid) filled on the pilot side of the operating piston 401, opposite the working side of the piston. When the injection pump 115 is actuated, the working side of the piston causes the pilot fluid in the crossflow channel 122a to be operatively displaced to actuate the diaphragm 111 of the mixing pump. On the working side of the operating piston 401, the crossflow channel 122a and the pump orifice 116 also contain a certain amount or volume of pilot fluid, as previously described herein. In one embodiment, oil can be used as the pilot fluid.

[0228] A pressure-balanced intermediate chamber 404 is fluidly connected to a pressure control device 410 via a flow conduit 406. The pressure control device 410 is configured and operable to regulate the pressure within the intermediate chamber during mixing pump operation such that the pilot fluid pressure in the intermediate chamber is lower than the pilot fluid pressure on the working side of piston 401. In one embodiment, the pilot fluid can be used both in the intermediate chamber 404 and in the crossflow channel 122a, on the working side of the operating piston 401 between the piston and the diaphragm 111 of the mixing pumps M1-M4, as previously described herein. This is advantageous in the event of any leakage at the seals on the operating piston 401 between the intermediate chamber 404 and the working side of the operating piston. A pilot fluid reservoir 413 can be incorporated in the flow conduit 406 and fluidly positioned between the pressure control device 410 and the intermediate chamber 404 of the operating piston assembly 400a. The pilot fluid reservoir holds a volume of pilot fluid subjected to a negative pressure (vacuum) applied by the pressure control device 410.

[0229] Specifically, the pressure control device 410 is configured to control and set the pressure of the pilot fluid in the intermediate chamber 404 during the return stroke of the injection pump 115 (i.e., when the diaphragm 111 of the mixing pumps M1-M4 is pulled back into the recess of the pumping chamber 112). At this time, a vacuum is created in a first pressure zone on the working side of the main operating piston 401, which is in fluid communication with the pumping chamber 112 via a crossflow channel 122a, as previously described herein. In one embodiment, the pressure control device 404 may be a commercially available vacuum pump, which may include a user-adjustable vacuum regulator 411, thereby providing a means to allow setting the pressure within the intermediate chamber 404. The vacuum pump is in fluid connection to the intermediate chamber 404 of the piston assembly 400a via fluid penetration in the pump orifice 116.

[0230] During operation, the pressure control device 410 evacuates the intermediate chamber 404 of the operating piston assembly 400a through the pump orifice 116, causing the pilot fluid pressure in this pressure zone to be lower than the pilot fluid pressure in the pressure zone formed on the working side of the operating piston 401. During the return stroke of the operating piston 401a, the pilot fluid pressure in the working side pressure zone preferably remains higher than the pilot fluid pressure in the pilot side pressure zone formed by the intermediate chamber 404 during the pump return stroke. This ensures that any air leaking into the pumping system will flow into the lower pressure zone in the intermediate chamber.

[0231] In summary, since positive pressure oil is easier to seal, it is possible to apply suction to the back side of the main oil seal (e.g., the main operating piston 401) within the pressure-balanced intermediate chamber 404 via pressure control device 410 to reduce the pilot fluid pressure therein. This results in the pilot fluid pressure on the operating side of the operating piston 401 acting on the mixing pump diaphragm 111 being higher than the pilot fluid pressure contained in the pressure-balanced intermediate chamber 404 between pistons 401 and 402. When this occurs, the pilot fluid on the operating side cannot draw air into the fluid. Since pistons 401 and 402 have the same area and are connected together by connecting member 405, there is no net force acting on the pistons.

[0232] Furthermore, when a fluid such as oil is used as a pilot fluid on both sides of the main operating piston 401, the fluid can be maintained in a pressure-balanced intermediate chamber 404 so that the main sealing interface formed by the main operating piston 401 and the inner surface of the pump port 116 is in an oil-to-oil sealing state, rather than an oil-to-air sealing state that is more difficult to achieve.

[0233] To further mitigate any potential air leakage into the pumping system, a piston assembly of the same type can be incorporated into the pressure relief system of the mixing pumps M1-M4. Specifically, the pressure relief piston assembly 420 can be slidably disposed within the pressure relief port 122 of the pump body 110. The piston assembly 420 includes a pressure relief piston 421, which is connected to a spaced-apart second sealing piston 422 via a connecting member 423. The piston assembly 420 can be identical to and include the same features as the previously described operating piston assembly 400a, such as the seal 403. A second intermediate chamber 425 is formed between pistons 421 and 422. The pressure relief spring 124 remains stationary and acts on the piston assembly.

[0234] In one embodiment, the second intermediate chamber 425 of the pressure relief piston assembly 420 may be fluidly connected to the first intermediate chamber 404 of the operating piston assembly 400a via a pressure balancing channel 424 formed laterally through the pump body 110 between the pump port 116 and the pressure relief port 122. Thus, the pump port 116 and the pressure relief port 122 are in fluid communication, which in turn allows the intermediate chambers 404 and 425 to be in fluid communication with each other. The pressure balancing channel 424 extends laterally through the pump body 110 and, as shown, is fluidly connected to the pump port 116 and the pressure relief port 122 in the intermediate portion of the hole between the ends of the pump port 116 and the pressure relief port 112. The pressure balancing channel 424 is positioned such that the intermediate chambers 404 and 425 remain fluidly connected throughout the entire axial range of motion of the pump piston 117 during the pumping and return strokes (see, for example...). Figure 39 and Figure 40 ).

[0235] The intermediate chamber 425 of the pressure relief piston assembly 420 defines a third pressure zone. In operation, when the pressure control device 410 (e.g., a vacuum pump) evacuates the pressure zone formed by the intermediate chamber 404 of the operating piston assembly 400a, this vacuum or negative pressure is applied to the intermediate chamber 425 in the pressure relief port 122 via the pressure balancing channel 424. Therefore, the pressures (negative pressure or vacuum) in the two intermediate chambers 404, 425 are equal. Thus, the arrangement of the pressure balancing channel 424 advantageously allows for a single vacuum pump to be provided as a common pressure control device, which simultaneously controls the pressures in both intermediate chambers, thereby avoiding the cost of providing a second vacuum pump for the pressure relief system.

[0236] Figure 39 The operating piston assembly 400a is shown when the pumping stroke of the injection pump 115 ends and the return stroke begins. Figure 40The operation via linear actuator 119 is shown, with the operating piston assembly retracting deeper and more completely into pump orifice 116 after the full return stroke. Notably, at the beginning and end of the pump return stroke, intermediate chambers 404 and 425 maintain fluid communication via proper positioning of pressure balancing channel 424 in pump body 110.

[0237] pilot fluid air removal system

[0238] According to another aspect of the invention, an air removal system 500 is provided, configured to actively remove air that may infiltrate and become entrained in the pilot fluid, thereby causing the potential process fluid pumping problems and inaccuracies described above. In one embodiment, the air removal system 500 is a vacuum-operated system, as further described below. Figures 41 to 49 One possible, but not limiting, embodiment of an air removal system is shown. A mixing pump M1 is shown as a non-limiting example of its application to an air removal device.

[0239] The air removal system includes an air removal device 502, which is fluidly connected to an internal reservoir (container) of pilot fluid within a mixing pump body 110, the internal reservoir being primarily defined by a pump port 116, a pressure relief port 122, and a crossflow channel 122a. The air removal device 502 includes a housing 501, which is mechanically connected to the fluid component body (e.g., the mixing pump body 110). In one embodiment shown, the housing 501 is generally cylindrical; however, other configurations are also possible, including but not limited to cuboids, hexagons, octagons, etc. The invention is not limited to the selected housing shape.

[0240] The device housing 501 includes a receiver 503 for an internal membrane, in which an air-permeable membrane 504 is disposed. The receiver 503 is fluidly connected to a reservoir of pilot fluid inside the pump body 110 via an air inlet 508 on one side of the membrane. On the opposite side of the membrane, the receiver 503 is fluidly connected to a vacuum source 510 via an air outlet 509. The vacuum source applies a negative pressure to the membrane to extract air entrained in the pilot fluid (if present in the fluid) through the air outlet 509 and the membrane. In one embodiment, the air inlet 508 is an internal fluid passage defined by the housing, which may include a rod 508a projecting outward from the housing 501 as shown, for connecting an air removal device to the pump body 101. This rod may be at least partially insertable into an opening in the flow passage of the pump body 110 containing the pilot fluid, such as a pilot fluid filling port defined by a reduced-diameter commutation orifice 122b associated with the aforementioned pressure relief orifice 122. Therefore, the air inlet 508 has a portion extending through the housing 501 and a continuous portion within the rod (see example...). Figure 49 The pilot fluid fills the air inlet up to membrane 504 and maintains wetted contact with the membrane. The pilot fluid side of the membrane is the wet side, while the opposite side of the membrane exposed to vacuum is the dry side.

[0241] In addition to the pilot fluid filling port, the housing 501 of the air removal device 502 can also be fluidly connected to the pump body 510 at any other suitable available port in fluid communication with the pilot fluid, or via a dedicated, independent, discrete port formed through the pump body 510 in fluid communication with the pilot fluid. Due to the clustered mixing pump arrangement, it may not be possible to directly connect the air removal device 502 to the pilot fluid filling port for each mixing pump M1-M4.

[0242] In other embodiments, the housing 501 of the air removal device 502 may be attached to other parts of the pump body 510, or it may not be physically attached to the pump body at all if there is sufficient space and clearance to prevent direct attachment. In the latter case, the air removal device may be fluidly connected to the pilot fluid only through a suitable port on the pump body (such as the pilot fluid filling port described above (i.e., the commutation port 122b)) or through a separate, discrete port formed through the pump body 510 that is in fluid communication with the pilot fluid.

[0243] An air outlet 509 extends internally through the housing 501. A fluid fitting 512 may be detachably attached to the housing at the air outlet for connection to an external flow conduit 510a, which is connected to a vacuum source 510, in one embodiment of which may be a vacuum pump. In some embodiments, the external flow conduit 510a may be a pipe or fitting. Any shape or type of fluid fitting 512 may be used.

[0244] In one embodiment, the membrane receiver 503 includes a wall 509a on the vacuum side of the membrane 504 and a second wall 509b facing each other on the pilot fluid side of the membrane. As shown, the walls may be formed at the bottom of a mating recess in the housing 501. Each of the walls 509a and 509b includes a plurality of mating airflow through openings 511a and 511b that are in fluid communication with the pilot fluid on one side of the membrane 504 and with a negative pressure (i.e., vacuum) generated by the vacuum source 510 on the other side. In one embodiment, the airflow through openings may be formed by arcuate slots to maximize the amount of air that can be extracted from the pilot fluid. However, any suitable shape or combination of shapes can be used. However, in one embodiment, each airflow through opening 511a preferably has a mating through opening 511b on the opposite side of the membrane 504, such that the openings on each side of the membrane are axially aligned with each other. This creates a continuous airflow path through the membrane while minimizing pressure drop to optimize the amount of air extracted from the pilot fluid.

[0245] In one embodiment, housing 501 may be formed by and include a first half-segment 501a that is detachably coupled to and mates with a second half-segment 501b. For example... Figures 44-45 and Figure 49 The membrane receiver 503, as best illustrated, is defined by receiver half 503a located in half segment 501a and receiver half 503b located in half segment 501b. Therefore, when the half segments of the housing are joined together, the membrane 504 is trapped between the half segments of the housing in the membrane receiver 503.

[0246] The housing segments 501a and 501b can be detachably connected by any suitable mechanical coupling. In one embodiment, a plurality of threaded fasteners 505 (e.g., bolts or screws) can be used. These fasteners are inserted through fastener openings 506 in segment 501a and threadedly engage with mating threaded sockets 507 formed in mating segment 501b. In other embodiments, sockets 507 can be replaced by through holes, and nuts can be screwed onto the exposed bottom threaded rods of the fasteners protruding beyond the through holes to secure the segments together. Other types of fastener arrangements and other types of fastening techniques can also be used.

[0247] The air-permeable membrane is formed of a material and configured to create a transportable gas interface (air being a gas) between a pilot fluid and a vacuum side of the membrane, which prevents liquids (such as the pilot fluid) from passing through. This allows air entrained in the liquid to be extracted through the membrane via vacuum / negative pressure, while retaining the liquid pilot fluid on the pilot fluid side of the membrane. In one embodiment, the membrane may be formed of silicone rubber; however, other materials may also be used.

[0248] As described herein, the agricultural sample processing and analysis systems and related processing / methods disclosed herein can be used to process and test a variety of agricultural materials and substances, such as, but not limited to, soil, vegetation / plants, fertilizers, feed, dairy products, or other agricultural materials, to obtain relevant parameters and analytes of agricultural interest. In particular, embodiments of the systems disclosed herein can be used to test numerous chemically relevant parameters and analytes of interest (e.g., plant-available nutrients / chemicals) in areas other than soil and plant / vegetation sampling. The following are some non-limiting examples of parameters and analytes of agricultural interest (including soil and plants).

[0249] Soil analysis: nitrate, nitrite, total nitrogen, ammonium nitrogen, phosphate, orthophosphate, polyphosphate, total phosphate, potassium, magnesium, calcium, sodium, cation exchange capacity, pH value, percentage of cation base saturation, sulfur, zinc, manganese, iron, copper, boron, soluble salts, organic matter, excess lime, activated carbon, aluminum, amino sugar nitrate, ammonia nitrogen, chloride, carbon-nitrogen ratio, electrical conductivity, molybdenum, soil texture (sand, silt, clay), cyst nematode egg count, mineralized nitrogen, and soil porosity.

[0250] Plants / Vegetation: Nitrogen, nitrates, phosphorus, potassium, magnesium, calcium, sodium, cation base saturation percentage, sulfur, zinc, manganese, iron, copper, boron, ammonia nitrogen, carbon, chloride, cobalt, molybdenum, selenium, total nitrogen, and live plant parasitic nematodes.

[0251] Fertilizer: Moisture / Total Solids, Total Nitrogen, Organic Nitrogen, Phosphate, Potassium, Sulfur, Calcium, Magnesium, Sodium, Iron, Manganese, Copper, Zinc, pH, Total Carbon, Soluble Salts, Carbon-to-Nitrogen Ratio, Ammoniacal Nitrogen, Nitrate Nitrogen, Chloride, Organic Matter, Ash, Electrical Conductivity, Kjeldahl Nitrogen, Escherichia coli, Fecal Coliforms, Salmonella, Total Kjeldahl Nitrogen, Total Phosphate, Oxalic Acid, Nitrate Nitrogen, Water-Soluble Nitrogen, Water-Insoluble Nitrogen, Ammoniacal Nitrogen, Humic Acid, pH, Total Organic Carbon, Bulk Density (Compacted), Moisture, Sulfur, Calcium, Boron, Cobalt, Copper, Iron, Manganese, Arsenic, Chloride, Lead, Selenium, Cadmium, Chromium, Mercury, Nickel, Sodium, Molybdenum, and Zinc.

[0252] Feed: Alanine, Histidine, Proline, Arginine, Isoleucine, Serine, Aspartic Acid, Leucine, Threonine, Cystine, Lysine, Tryptophan, Glutamic Acid, Methionine, Tyrosine, Glycine, Phenylalanine, Valine (crude protein required), Arsenic, Lead, Cadmium, Antimony, Mercury.

[0253] Vitamin E (β-tocopherol), Vitamin E (α-tocopherol), Vitamin E (δ-tocopherol), Vitamin E (γ-tocopherol), Vitamin E (total), Moisture, Crude Protein, Calcium, Phosphorus, Acid Detergent Fiber (ADF), Ash, Total Digestible Nutrients (TDN), Energy (Digestible and Metabolizable), Net Energy (Weight Gain, Lactation, Maintenance), Sulfur, Calcium, Magnesium, Sodium, Manganese, Zinc, Potassium, Phosphorus, Iron, Copper (not applicable to premixes), Saturated Fat, Monounsaturated Fat, Omega-3 Fatty Acids, Polyunsaturated Fat, Trans Fat Fatty acids, omega-6 fatty acids (requires crude or acidic fats), glucose, fructose, sucrose, maltose, lactose, aflatoxins (B1, B2, G1, G2), deoxynivalenol (DON), fumonisin, ochratoxin, T2-toxin, zearalenone, vitamins B2, B3, B5, B6, B7, B9 and B12, calories, chloride, crude fiber, lignin, neutral detergent fiber, non-protein nitrogen, selenium, total iodine, total starch, vitamin A, vitamin D3 and free fatty acids.

[0254] Feed: Moisture, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), net energy (weight gain, lactation, maintenance), relative feed value, nitrates, sulfur, copper, sodium, magnesium, potassium, zinc, iron, calcium, manganese, sodium, phosphorus, chloride, fiber, lignin, molybdenum, hydrocyanic acid, and selenium (compliant with United States Pharmacopeia standards).

[0255] Milk components: milk fat, true protein, somatic cell count, lactose, other solids, total solids, added water, lacturea nitrogen, acidity, pH, antibiotic test and microbiology.

[0256] control system

[0257] Figure 2 This is a schematic system diagram illustrating a control or processing system 2800, which includes a central processing unit (CPU) or system controller 2820 based on a programmable processor, as referenced herein. The system controller 2820 can be operatively and communicatively coupled to... Figure 3 All functional flow control components shown (e.g., pumps, valves, etc.), plasma torch device 200, and spectrometer 300. This controller can control the operation, sequence, and timing of the various processes described herein, including the processing and analysis of agricultural sample fluids.

[0258] System controller 2820 may include one or more processors, non-transitory tangible computer-readable media, programmable input / output peripherals, and all other necessary electronic accessories typically associated with a full-featured processor-based controller. System control system 2800, including controller 2820, is operatively and communicatively linked via appropriate communication links to the various soil sample processing and analysis systems and apparatuses described elsewhere herein, in order to control the operation of these systems and apparatuses in a fully integrated and sequential manner.

[0259] refer to Figure 2 According to one embodiment, the control system 2800, including a programmable controller 2820, can be mounted at any location on a fixed support, or conversely, it can be mounted on a translationally movable self-propelled or traction machine (e.g., a vehicle, tractor, combine harvester, etc.), which may include agricultural implements (e.g., seeders, cultivators, plows, sprayers, spreaders, irrigation implements, etc.). In one example, the machine performs the operation of a tractor or vehicle coupled to an agricultural implement 2840 for agricultural operations. In other embodiments, the controller may be part of a fixed station or facility.

[0260] The control system 2800 (whether an onboard control system for a translatable machine or an external control system) typically includes a controller 2820, a non-transitory computer- or machine-accessible and readable medium (such as memory 2805), and a network interface 2815. The computer- or machine-accessible and readable medium may include any suitable volatile and non-volatile memory or means operable and communicatively coupled to one or more processors. Any suitable combination and type of volatile or non-volatile memory may be used, including, but not limited to: random access memory (RAM) and its various types, read-only memory (ROM) and its various types, hard disks, solid-state drives, flash memory, or other memory and means that can be written to and / or read by a processor operablely coupled to the medium. Both volatile and non-volatile memory can be used to store program instructions or software. In one embodiment, the computer- or machine-accessible and readable non-transitory medium (e.g., memory 2805) contains executable computer program instructions that, when executed by the system controller 2820, cause the system to perform operations or methods of this disclosure, including measuring the performance of soil and plant samples and their tests. Although machine-accessible and readable nontransitory media (e.g., memory 2805) are shown as a single medium in exemplary embodiments, the term should be considered to include single or multiple media (e.g., centralized or distributed databases, and / or associated caches and servers) that store one or more sets of control logic or instructions. The term "machine-accessible and readable nontransitory media" should also be considered to include any medium capable of storing, encoding, or carrying a set of instructions to be executed by a machine and to enable the machine to perform any or more methods of this disclosure. Therefore, the term "machine-accessible and readable nontransitory media" should also be considered to include, but is not limited to, solid-state memory, optical and magnetic media, and carrier signals.

[0261] Network interface 2815 is connected to agricultural (e.g., soil or other) sample processing and analysis systems (and related devices) described elsewhere. Figure 2 The system communicates with other systems or devices, including but not limited to the machine 2840 which has its own controller and equipment.

[0262] The programmable controller 2820 may include one or more microprocessors, processors, system-on-a-chip (integrated circuits), one or more microcontrollers, or combinations thereof. The processing system includes processing logic 2826 for executing software instructions for one or more programs, and communication modules or units 2828 (e.g., transmitters, transceivers) for transmitting and receiving messages from a network interface 2815 and / or an agricultural sample processing and analysis system 2803, which includes a sample preparation subsystem 3002 and the components described herein (including a closed-loop slurry circulation loop 8002 component). The communication unit 2828 may be integrated with the control system 2800 (e.g., controller 2820) or separate from the programmable processing system.

[0263] The programmable processing logic 2826 of the control system 2800 (which directs the operation of the system controller 2820, which includes one or more processors) can process messages received from the communication unit 2828 or the network interface 2815, including agricultural data (e.g., test data, test results, GPS data, liquid application data, flow rate, etc.) and data generated by the soil sample processing and analysis system 2803. The memory 2805 of the control system 2800 is configured to pre-program variable or setpoint / baseline values, store collected data, and computer instructions or executable programs (e.g., software 2806) for controlling the operation of the controller 2820. The memory 2805 may store, for example, software components of test software used to analyze soil and vegetation samples to perform operations of this disclosure, or any other software application or module, images 2808 (e.g., captured crop images), alarms, maps, etc. The control system 2800 may also include an audio input / output subsystem (not shown), which may include a microphone and speaker for, for example, receiving and sending voice commands or for user authentication or authorization (e.g., biometrics).

[0264] The system controller 2820 communicates bidirectionally with the memory 2805 via communication link 2830, bidirectionally with the network interface 2815 via communication link 2832, bidirectionally with the display device 2830 and an optional second display device 2825 via communication links 2834 and 2835, and bidirectionally with the I / O port 2829 via communication link 2836. The system controller 2820 can also communicate with the soil sample processing and analysis system 2803 via wired / wireless communication link 5752, via the network interface 2815, and / or directly, as shown in the figure.

[0265] Display devices 2825 and 2830 can provide a visual user interface for users or operators. The display device may include a display controller. In one embodiment, display device 2825 is a portable tablet or computing device with a touchscreen that displays data (e.g., soil test results; vegetation test results; liquid application data; captured images; localized view layers; high-resolution field maps of real-time liquid application data, real-time sowing or harvesting data, or other agricultural variables or parameters; yield maps; alarms, etc.) and data generated by agricultural data analysis software applications, and receives input from users or operators to obtain a decomposed view of the field area, thereby monitoring and controlling field operations. These operations may include machine or implement configuration, data reporting, control of machines or implements including sensors and controllers, and storage of the generated data. Display device 2830 may be a display (e.g., a display provided by an original equipment manufacturer (OEM)) that displays images and data for partial view layers, liquid application data for immediate application, data for immediate sowing or immediate harvesting, yield data, thereby controlling machines (e.g., seeders, tractors, combine harvesters, sprayers, etc.), manipulating machines, and monitoring machines or implements connected to machines (e.g., seeders, combine harvesters, sprayers, etc.) using sensors and controllers located on the machine or implements.

[0266] Figures 50-55 and Figures 68-71 An alternative embodiment of the body 210-1 of the plasma torch device 200 is shown. (Compared to...) Figures 30-38 Unlike the one-piece integral body 210 shown, body 210-1 is a two-piece body, comprising an upper body portion 210-2 and a lower body portion 210-3 spaced apart from the upper body portion. The two-piece body 210-1 defines a top 211-1, a bottom 212-1, and four adjacent sides 213-1. In the non-limiting embodiment shown, both the upper and lower body portions have a rectangular-cubic configuration; however, other suitable configurations may also be used. The positioning and arrangement of the plasma torch device components are substantially the same. For example, a plasma chamber 202 is formed in the vertical space between the upper and lower body portions. The anode needle 205 and its associated accessories are disposed in the upper body portion 210-2. The cathode tube 203, waste tank 215, and their associated accessories are disposed in the lower body portion 210-3.

[0267] In a non-limiting embodiment, the upper and lower body portions of the two-piece body 210-1 are detachably connected together via a plurality of elongated, vertically oriented support members (such as support columns 210-4). In one embodiment, four horizontally / laterally spaced support columns may be provided; each support column is located near one of the four corner regions 210-6 of the plasma torch body 210-1. The support columns can have any suitable shape (such as a cylindrical shape as shown in the figure) or another shape (including straight, hexagonal, or other shapes). The support columns 210-4 are connected via threaded fasteners 210-5 (e.g., see...). Figure 68 The support post 210-4 is detachably connected to the upper and lower body sections to allow disassembly of the two-piece assembly, thereby improving access to the anode needle 205, cathode tube 203, and other accessories for servicing or replacement. The end of the support post 210-4 may include a threaded socket 210-7 (not shown), into which a fastener 210-5 can be threaded after being inserted through a connection opening 210-8 in the upper and lower body sections 210-2 and 210-3. In a non-limiting embodiment, the support post is preferably made of metal, such as aluminum, steel, or other metals.

[0268] It is worth noting that the one-piece integral plasma torch body 210 or the two-piece plasma torch body 210-1 of the plasma torch device 200 with spectrometer can be used either in conjunction with the manifold blocks M1-M4 described earlier herein, or as a separate, independent spectroscopic analysis system. Therefore, in some embodiments, the body 210 or 210-1 is not physically connected to the manifold block, but is fluidly connected to it via a suitable flow conduit.

[0269] Alternative embodiments of lens cleaning system

[0270] Figures 50-67 An alternative embodiment of a lens cleaning system is shown, which blows an airflow onto the outer exposed surface 302a of a lens 302, which faces inward toward the plasma chamber 202 and the plasma torch 201, which generates plasma from a sample fluid when energized. As previously described herein, the lens is susceptible to fogging due to the generation of plasma, which, along with moisture, may splash onto the exposed surface of the lens. This embodiment of the lens cleaning system avoids the need and cost of machining dedicated holes in the solid portion of the body 210 of the plasma torch assembly 200 for forming an air inlet channel 221 and an air outlet channel 222, and for inserting and supporting the spectrometer's light-collecting tube 301, as shown. Figures 37-38As shown. In this embodiment, this situation is avoided by providing an air shroud 610 that is detachably and directly connected to the light-collecting tube 301 of the spectrometer, as will be further described below.

[0271] refer to Figures 50-67 If applicable, the lens cleaning system 600 includes an air shroud 610 that can be coupled to the light-collecting tube 301 of the spectrometer 300. The air shroud 610 is configured to receive a pressurized airflow at least when the plasma torch device 200 is operating to generate plasma and to discharge / blow a pressurized airflow to a minimum amount onto the exposed surface 302a of the lens 302 mounted at the innermost end of the light-collecting tube 301.

[0272] The spectrometer 300 includes a housing 304 of any suitable configuration, which in one embodiment encloses the spectrometer's electronic components and cantileveredly supports the light-collecting tube 301. The spectrometer housing 304 can be mounted to and supported by the body 210 of the plasma torch apparatus 200 via a suitably configured mounting bracket 305, which is coupled to the body 210 (see, for example...). Figures 50-51 The housing 304 also supports the combined power / data cable 306.

[0273] See Figure 57 The light-collecting tube 301 has a generally cylindrical, elongated hollow tubular body 301c, comprising a distal end 301a closest to the plasma torch 201, a proximal end 301b furthest from the plasma torch 201 and closest to the spectrometer housing 304, and a cylindrical sidewall 301c extending between the distal and proximal ends. A light-transmitting passage 303 extends axially from the proximal end 301b to the distal end 301a between the tubular body of the light-collecting tube 301 and through the tubular body, for collecting light emitted by the excited plasma generated by the plasma torch 201 in the plasma chamber 202 and transmitting the light to the electronic circuitry in the spectrometer 300 for analysis as previously described herein and typically for a spectrometer. The light-collecting tube 301 defines a longitudinal tube axis At, which extends between the distal end 301a and the proximal end 301b and passes through the geometric center of the light-collecting tube.

[0274] Lens 302 is supported by the distal end 301a of light-collecting tube 301 and defines an inwardly facing exposed surface 302a that faces the plasma torch 201 in the plasma chamber 202. The lens can have any suitable profile selected to collect light emitted by the plasma and transmit that light inward through the light-collecting tube to the analytical electronics of the spectrometer 300. The exposed surface 302a of lens 302 opens into the plasma chamber 202 and is therefore subject to fogging by moisture ejected outward by the plasma formed from the energized sample fluid. In one embodiment, light-collecting tube 301 may be supported solely by the housing 304 of the spectrometer 300 and protrude from the spectrometer into the plasma chamber 202 in a cantilevered manner as shown. Therefore, as previously discussed... Figures 37-38 Unlike the spectrometer embodiments described herein, the light-collecting tube does not require support from the body 210 of the plasma torch device 200.

[0275] Continue to refer to Figure 57 The air shroud 610 has an elongated hollow tubular body 614, comprising a distal end 612 closest to the plasma torch 201, a proximal end 611 furthest from the plasma torch 201, and a generally sidewall 613 extending between the distal and proximal ends. The air shroud 610 defines a longitudinal air shroud axis As that extends between the proximal end 611 and the distal end 612 and passes through the geometric center of the air shroud. When the air shroud 610 is detachably coupled to the light collector tube 301, the air shroud is coaxial with the light collector tube (i.e., the light collector tube axis At and the air shroud axis As are coaxially aligned). The outer surface of the hollow tubular body 614 of the air shroud (i.e., the sidewall 613) can have any suitable shape or profile or combination thereof. In the non-limiting embodiment shown, the sidewall 613 comprises a combination of arcuate curved surfaces separated by flat surfaces, which can facilitate machining various features and openings in the air shroud 610 due to locking clamps and / or for other purposes.

[0276] To attach and secure the air shroud 610 to the light-collecting tube 301, the air shroud includes an axially extending central passage 616 into which the light-collecting tube is slidably inserted from a proximal end 611 of the air shroud. The central passage 616 extends between and through the proximal end 611 and the distal end 612 of the air shroud. Therefore, the cross-sectional shape of the central passage 616 of the air shroud is configured to complement the cross-sectional shape of the light-collecting tube 301 to receive and at least partially enclose the light-collecting tube therein. In one embodiment, the central passage 616 and the light-collecting tube 301 may each have a circular cross-sectional shape. The central passage 616 terminates at an axial aperture 615 at the distal end 612 of the air shroud; this axial aperture is axially aligned with the lens 302 such that the line of sight of the spectrometer 300 passes through the lens and the axial aperture into the plasma chamber 202 for collecting light emitted by the plasma formed by the plasma torch 201, as previously described herein. The axial hole 615 can be circular and coaxially aligned with the air shroud axis As.

[0277] The distal portion of the central passage 616 adjacent to the distal end 612 of the air hood 610 may include, for example: Figure 57 The optimally illustrated frustoconical section 620. The inner surface 616a of the air shroud sidewall 613 gradually converges within the frustoconical section, but remains straight in the remaining portion of the air shroud towards the proximal end. Therefore, the diameter of the central passage 616 at the frustoconical section gradually decreases towards the distal end 612 of the air shroud 610. This results in the diameter D1 of the axial aperture 615 of the air shroud 610 (formed by the end of the frustoconical section 620) being smaller than the diameter D2 of the central passage at the proximal end 611 of the air shroud, and also smaller than the diameter of the portion of the central passage immediately adjacent to the frustoconical section before it begins to converge and decrease in diameter. The decreasing diameter of the central passage 616 at the distal end of the air shroud not only defines the decreasing diameter axial aperture 615, but also causes and guides most of the pressurized air injected into the air shroud via the inlet port 618 to flow through and through the outlet port 619, rather than flowing inward through the axial aperture towards the plasma torch 201. This prevents a large amount of air from escaping into the plasma chamber 202 through the axial hole 615 and reaching the plasma, thus destabilizing the plasma and making it difficult to maintain plasma excitation.

[0278] While it may be preferred to include a truncated cone section 620 in the air shroud 610 for the reasons stated above, in other embodiments, the truncated cone section may be omitted if the distance between the light collector 301 and the air shroud and the plasma torch 201 is sufficient to prevent the plasma from being disturbed by air escaping through the axial hole 615 and flowing toward the plasma.

[0279] As further described herein, the air shroud 616 preferably at least encloses the distal end 301a of the receiving lens 302 of the light-collecting tube 301 to prevent fogging of the lens. Therefore, in this embodiment, the light-collecting tube is only partially inserted into the central passage 616 of the air shroud 610. In this embodiment, the axial length (end-to-end measurement) of the air shroud 610 may be less than the axial length of the light-collecting tube 301. The proximal portion of the light-collecting tube may remain exposed.

[0280] However, in another embodiment, as shown, the light collector 301 can be fully inserted into the central passage 616, such that the entire length of the light collector 301 from its proximal end 301b to its distal end 301a is nested and surrounded by the air shroud 610 (see example). Figure 56 This simplifies the installation and proper positioning of the air hood on the light collector tube because the proximal end 611 can abut against the outer surface of the housing 304 of the spectrometer 300 and use it as a travel stop to ensure the proper positioning of the air hood's inlet port 618 and outlet port 619 relative to the lens 302 for defogging. In this embodiment, as shown, the axial length (end-to-end measurement) of the air hood 610 can be greater than the axial length of the light collector tube 301.

[0281] The air supply aspect of the air hood 610 includes an inlet port 618 and an outlet port 619, which are configured and arranged to cooperate with each other to blow a stream of defogging pressurized air across the exposed surface 302a of the light-collecting tube lens 302 in a direction transverse to the light-collecting tube axis At and the air hood axis As. In one embodiment, the airflow can be essentially continuous while the plasma torch 201 is operating, forming a protective air curtain above the lens to prevent fogging of the lens due to moisture splashing caused by plasma generated by the plasma torch in the plasma chamber 202. This includes any moment when sample fluid flows toward the plasma torch 201, which can include before and, of course, when the plasma is excited. The airflow can also form an air curtain even when the plasma is not excited, and an air curtain can also be formed when liquid is injected or sprayed into the plasma chamber, for example, when rinsing with water between sample fluid processing steps to prevent sample cross-contamination.

[0282] The air inlet port 618 and the air outlet port 619 extend laterally perpendicular to the air shroud axis As through the sidewall 613 at the distal end 612 of the air shroud 610 and open into the central passage 616. In one embodiment, the air inlet port and the air outlet port may be positioned diametrically opposed at the distal end of the air shroud as shown in the figure (see example...). Figures 56-57In the illustrated embodiment, for a design including a central passage 616 with such a diameter-reducing section, the inlet and outlet ports are located in the frustoconical section 620 of the air shroud, near the distal end 612 and the axial bore 615. In other designs that omit the frustoconical section, the inlet and outlet ports may still be located in the same positions as described and shown above.

[0283] In a non-limiting embodiment, the cross-sectional flow area of ​​the inlet port 618 is preferably smaller than that of the outlet port 619 to guide the airflow discharged from the inlet port toward the outlet port and to allow it to continue flowing in the same direction as in the central passage 616 into the air shroud from the inlet port. It is noteworthy that, due to the momentum of the airflow, most of the air will travel along a straight path from the inlet port to the outlet port, rather than making a right-angle turn through the axial hole 615 as described above (although some minor leakage through the axial hole may occur due to turbulence in the airflow). In other embodiments, it is possible that the inlet and outlet ports may have the same cross-sectional flow area.

[0284] In one embodiment, the inlet port 618 may be circular in shape, and the outlet port may include an elongated slot. This slot is arc-shaped, conforming to the cylindrical shape of the air shroud sidewall 613. The inlet port 618 and outlet port 619 are arranged to discharge compressed air tangentially across the exposed surface 302a of the lens 302 to form a protective, light-transmitting air curtain between the lens and the plasma torch 201, deflecting water-containing liquid splashes generated by the plasma and preventing them from reaching the lens and forming fog on it. The splashes are thus redirected away from the lens by the protective airflow and are entrained in the airflow discharged through the outlet port 619. The outlet port is configured to discharge air received from the inlet port 618 into the plasma chamber 202 in a direction not toward the plasma torch to avoid affecting the stability of the excited plasma. In one embodiment, air is discharged from the outlet port into the plasma chamber 202 in a direction transverse to the air shroud axis As.

[0285] The air intake port 618 of the air shroud 610 is fluidly connected to the pressurized air source 223 via a suitable airflow duct 617 (see example). Figure 56 In one embodiment, the airflow duct may be a rigid or flexible tube. The airflow duct 617 is configured to extend through a portion of the plasma chamber 202 to connect to the inlet port 618 and may be exposed to the environment within the plasma chamber. In some embodiments, for convenience, a commercially available push-in quick-connect fitting can be used to detachably connect the airflow duct 617 to the inlet port. However, other types of fluid connections may also be used.

[0286] The air shroud 610 can be detachably secured to the light-collecting tube 310 of the spectrometer 300 via any suitable detachable mechanical coupling mechanism. In one embodiment, a threaded fastener 622 can pass through a mating threaded through-hole 621 formed in the sidewall 613 of the air shroud to engage an annular fastening recess 623 formed on the outside of the light-collecting tube 301 (see, for example...). Figure 57 and Figure 58 In one non-limiting embodiment, fastener 622 may be a positioning screw; however, other types of screws may also be used, including screws with enlarged heads. When the fastener is fully tightened, the end of the fastener shank enters the recess and engages with the light-collecting tube body within the recess. This axially locks the air shroud onto the light-collecting tube, thereby preventing the air shroud from being pulled out of the light-collecting tube in the axial direction.

[0287] The process or method for connecting the air shroud 610 to the light-collecting tube 301 of the spectrometer 300 is summarized below. (Reference) Figures 56-57 First, align the air shroud 610 axially with the light-collecting tube, positioning the proximal end 611 of the air shroud's opening adjacent to the distal end 301a of the light-collecting tube 301. Align the longitudinal axis At of the light-collecting tube with the longitudinal axis As of the air shroud. Then, insert the distal end 301a of the light-collecting tube 301 axially into the proximal end of the air shroud 610 and into the central passage 616 of the air shroud. Next, advance the air shroud 610 axially onto the light-collecting tube 301 until the lens 302 is positioned adjacent to the truncated cone section 620 of the central passage 616 of the air shroud, as well as the inlet port 618 and outlet port 619 (e.g., ...). Figure 56 (As shown). Considering it from another angle, the light collector 301 advances axially through the central passage 616 of the air shroud until the lens 302 is positioned adjacent to the frustoconical segment 620. The result is the same.

[0288] In one embodiment, the air shroud 610 can be advanced onto the light collector tube 301 until its proximal end 611 abuts against the outside of the assembly spectrometer housing 304. This ensures that the light collector tube is fully inserted into the air shroud and that the lens 302 is correctly positioned relative to the inlet and outlet ports. This also ensures that the threaded through-hole 621 on the sidewall 613 of the air shroud 610 is axially aligned with the annular fastening recess 623 on the outer surface of the light collector tube 301. The threaded fastener 622 is then screwed into the threaded through-hole 621 and engages with the light collector tube 301 in the recess 623 to axially lock the air shroud onto the light collector tube. Once the air shroud is locked in place by the fastener, the air shroud 610 can no longer be axially withdrawn from the light collector tube 301. To remove the air shroud from the light collector tube, simply reverse the above process.

[0289] During the lens defogging operation after the air shroud 610 has been installed on the light-collecting tube 301 of the spectrometer 300, pressurized air from the air source 223 flows into the air inlet 618 of the air shroud, such as... Figure 56 The solid line directional arrows indicate the airflow direction. Air is discharged into the truncated conical section 620 of the air shroud 610 at the distal portion of the central passage 616 of the air shroud 610 and in front of the lens 302 at the distal end of the light-collecting tube 301. As shown, the air flows tangentially in front of and across the exposed surface 302a of the lens, and then exits from the outlet port 619 opposite to the inlet port. Any liquid splashes or moisture emitted by the plasma along the direction toward the lens 302 of the light-collecting tube may enter the axial aperture 615 of the air shroud 610, but it will be entrained in the blowing airflow and guided away from the lens through the outlet port 619 of the air shroud, thereby preventing the lens from fogging.

[0290] Plasma torch cleaning equipment

[0291] During the operation of the plasma torch apparatus 200 described earlier herein, the anode needle 205 and cathode tube 203 of the plasma torch 201, which dispenses agricultural sample fluids or other process fluids, may become contaminated with residues or deposits formed during plasma excitation, thus requiring cleaning. Although chemical cleaning fluids, such as nitric acid or another fluid, can be dispensed from the cathode tube between sample processing steps in the plasma torch 201 to help remove some accumulated dirt residues, the inventors have found that such chemical cleaning alone is insufficient to maintain the cleanliness of the cathode tube and anode needle in all cases. Contaminated anode needles and cathode tubes can adversely affect the accuracy of the results captured by the spectrometer from the plasma and may lead to cross-contamination between sample fluid processing steps. Some deposits may be ablated or baked by the high-temperature plasma. Therefore, periodic mechanical cleaning of the plasma torch 201, such as cleaning between processing steps, is desirable to supplement or replace chemical cleaning.

[0292] Figure 68-95One embodiment of a plasma torch cleaning apparatus 700 according to this disclosure is described, which is configured and operable to mechanically clean anode needles 205 and cathode tubes 203. The mechanical cleaning apparatus 700 generally includes: a housing 710 supporting a linear actuator 720; and an extendable and retractable brush holder 730 coupled to the actuator. In one embodiment, the brush holder supports one or more brushes 740 for cleaning the plasma torch. Preferably, in a non-limiting embodiment, a pair of brushes is provided to optimize surface coverage of the area of ​​the plasma torch to be cleaned, where residues may accumulate, and to conveniently optimize the overall cleaning efficiency during a single brush stroke, as further described herein.

[0293] Actuator 720 includes an elongated actuator body that slidably supports an extendable and retractable operating lever 722, which is movable in opposite linear directions along an actuation axis AA defined by the operating lever via actuation of the actuator. One of a pair of brushes 740 is disposed on each side of the actuation axis AA (e.g., see...). Figure 77 The actuator and cleaning device housing 710 are mounted to the plasma torch device in a vertical position such that the anode needle 205 and the cathode tube 203 are horizontally aligned with the actuation axis AA, which can extend through and intersect the gap formed between the anode needle and the cathode tube.

[0294] Actuator 720 can be any suitable commercially available linear actuator type, including electric linear actuators, air-operated actuators, oil-operated actuators, or other types of actuators. The accompanying drawings illustrate a pneumatic actuator including an axially elongated cylinder bore 723 and a piston head 724 slidably disposed within the cylinder bore and coupled to the inner end 725 of an operating rod 722 (see example...). Figures 79-80 A pair of air end holes 726 formed on the actuator body are in fluid communication with a cylinder bore 723 to actuate the actuator and cause the operating lever to retract or extend linearly in a known manner.

[0295] The housing 710 of the mechanical cleaning device 700 can have any suitable shape, configured and operable to both support the actuator 720 and detachably connect the plasma torch cleaning device 700 to the plasma torch assembly body 210. In one embodiment, the housing 710 comprises a generally block-shaped body having a walled structure including a top 710a, a bottom 710b, a front end 710c, a rear end 710d, and opposing lateral sides 710e extending between the front and rear ends. The ends and sides are defined by a rear wall 718a, a pair of laterally spaced front short walls 718b, and opposing lateral side walls 718c. The housing 710 can have a one-piece integral structure as shown, or it can comprise multiple components integrally joined together by suitable coupling methods known in the art (e.g., but not limited to welding, threaded fasteners, or other coupling methods).

[0296] The cleaning device housing 710 defines an upwardly opening actuator cavity 711 that removably receives a linear actuator 720 for at least partial mounting within the actuator cavity. For this purpose, in one embodiment, the actuator 720 may include a pair of laterally spaced rear fastener openings 715 formed through a rear end 710d in the actuator cavity 711. These rear fastener openings are concentrically aligned with a pair of mating, at least partially threaded holes 716 formed on the actuator body, extending from the actuator rear end 720b toward the front end 720a (see, for example...). Figure 79 In some embodiments, as shown, the hole 716 can extend completely through the actuator body from the rear end to the front end. A pair of threaded fasteners 729 are provided for mounting in the through opening 715 to thread into the hole 716, thereby detachably connecting the actuator 720 to the housing 710.

[0297] In one embodiment, to provide additional support, the body of the actuator 720 may be mounted on at least one horizontal support member of the housing, which may be an axially elongated support platform 712. In one embodiment, the support platform 712 includes a flat top surface and is disposed within the actuator cavity 711, with its bottom within the housing 710. In some embodiments as shown, a pair of laterally spaced support platforms 712 may be provided, defining an open axial channel 717 between the support platforms, the axial channel receiving a downwardly overhanging longitudinal protrusion 728 formed on the bottom of the actuator body (see, for example...). Figure 75Not all actuators include such a protrusion. Therefore, in cases where the actuator does not include the protrusion 728, a single support 712 is sufficient, which can form a fully or partially enclosed bottom for the housing. Depending on the configuration of the actuator body, other methods may also be used to support the actuator within the housing. It is worth noting that in some embodiments, the support 712 may be omitted if the actuator can be securely mounted within the actuator housing.

[0298] The actuator cavity 711 forms a generally U-shaped housing configuration and extends through the front end 710c of the housing, thereby defining an inlet opening 711a between the front short walls 718b that leads into the actuator cavity. The width of the inlet opening 711a is smaller than the rear portion of the actuator cavity 711 that holds the actuator 720. The brush holder 730 is at least partially received and retractable into the inlet opening and the front portion of the actuator cavity (see, for example, [reference needed]). Figure 79 The rear portion of the actuator cavity 711 is terminated by a rear wall 718a, which defines the rear end 710d of the housing 710. The sides of the actuator cavity are enclosed by a pair of side walls 718c. Therefore, the actuator cavity 711 is open to the front.

[0299] In one embodiment, the brush holder 730 may be block-shaped, having a linear configuration including a front portion 730a, a rear portion 730b, a top portion 730c, a bottom portion 730d, and a pair of opposing lateral portions 730e (see example...). Figure 74 The brush holder may also be rectangular-cubic in shape. The brush holder is detachably coupled to the outer end 726 of the actuator operating lever 722, for example via a threaded fastener 727 inserted through a central through-hole 731 in the brush holder. The brush holder 730 also includes a pair of laterally spaced brush mounting holes 732 configured to receive the shank 743 of the brush 740 therein. In one embodiment, the brush is coupled to the brush holder 730 via a locating screw 733. The locating screw threadly engages with a corresponding threaded retaining hole 734 extending through the brush holder 730, the threaded retaining hole intersecting perpendicularly to the brush mounting hole 732. A pair of threaded retaining holes 734 and locating screws 733 may be provided for each brush to provide two spaced-apart retention points along each brush shank; however, in other embodiments, a single threaded retaining hole and a single retaining screw may be provided for each brush. The central through-hole 731 and the brush mounting holes 732 are parallel to each other and extend from the front to the rear of the brush holder 730. A threaded retaining hole 734 extends downward from the top 730c of the brush holder 730 to intersect with the brush mounting hole 732. In other embodiments, the threaded retaining hole may alternatively be formed on the bottom of the brush holder and extend upward to the brush mounting hole.

[0300] Each brush 740 includes a brush head 741 comprising a plurality of radially extending and resilient flexible cleaning elements, such as bristles 742 coupled to a handle 743. In one embodiment, the handle 743, preferably formed of metal and substantially straight, can have any suitable style, such as a round handle (cylindrical), twisted handle, hexagonal handle, or others. The brush handle is received in a brush mounting hole 732 formed through the front end 730a of the brush holder 730 (see, for example...). Figure 74 and Figure 79 The brush mounting hole 732 extends at least partially through the brush holder from front to rear. In some embodiments, the brush mounting hole 732 may extend completely through the brush holder. A locating screw 733 is mounted in the brush mounting hole 732 to engage with a brush shank 743 to detachably attach the brush to the brush holder 730. If a threaded brush shank 743 is provided in some contemplated embodiments, the brush mounting hole 732 of the brush holder 730 may also be threaded to form a threaded connection therebetween, thus eliminating the need for the locating screw 733 and the corresponding locating screw fixing hole 734.

[0301] As shown in the figure, the array of bristles 742 on brush 740 can extend 360 degrees around the handle and along the handle for a predetermined length. In one embodiment, brush 740 can be a commercially available tube brush, such as the MMC4810A743 tube brush available from McMaster-Carr, or a similar brush from the same or other suppliers. The bristles 742 are preferably formed of a suitable metallic material to maximize scrubbing efficiency for removing deposits from the metal anode needles 205 and cathode tubes 203. For example, in one embodiment, stainless steel bristles can be used to avoid chemical reaction with nitric acid, which in a non-limiting embodiment can be used to excite the plasma, and the stainless steel bristles can also be used to chemically clean the cathode tubes 203 and anode needles 205 after each processing step of the sample fluid through the plasma torch apparatus 200. However, if other chemicals are used, other bristle materials can be used that make the bristles chemically resistant. Therefore, the selected brush material should remain chemically inert to any chemicals used in conjunction with the plasma torch for plasma excitation and / or cleaning. In some embodiments, non-metallic bristle materials (e.g., elastomeric materials formed of rubber or polymers) may also be suitable and applicable. If the cleaning element is formed of an elastomeric material, it may take on other shapes, such as a series of circular discs spaced apart on the brush handle or other shapes. Examples of polymers include, but are not limited to, nylon, polypropylene, and polyester.

[0302] Actuator 720 is configured and operable to move brush holder 730 with brush 740 between an extended position and a retracted position, in which a plurality of cleaning elements (e.g., brush bristles in one embodiment) slidably engage with an anode (e.g., anode needle 205) and a cathode (e.g., cathode tube 203) with a force sufficient to produce a scrubbing action, thereby cleaning the anode and cathode; in the retracted position, the cleaning elements are withdrawn and disengaged from the anode and cathode. In the extended position, the brush holder and brush are positioned distal to the cleaning device housing 710. In the retracted position, the brush holder and brush are positioned proximal to the cleaning device housing.

[0303] In one embodiment, the housing 710 of the plasma torch cleaning device 700 is configured to be detachably and slidably coupled to the body of the plasma torch device 200 to provide a vertical adjustment mechanism that facilitates proper alignment of the brush 740 with the cathode tube 203 and anode needle 205 of the plasma torch 201 for effective cleaning. In the illustrated non-limiting embodiment of the plasma torch cleaning device 700, the housing 710 may be configured to be mounted to, for example... Figures 68-71 The alternative two-piece plasma torch assembly body 210-1 is shown. In this embodiment, the housing 710 includes a pair of vertical mounting through-holes 721 formed near the front end 710c of the housing, the front end face 710c facing the plasma torch 201 (e.g., the anode needle 205 and cathode tube 203 assembly in the plasma chamber 202). The through-holes 721 extend from the top of the housing to the bottom and pass completely through the top to the bottom of the housing. Each through-hole 721 slidably receives one of a corresponding pair of support posts 210-4 of the body 210-1 (see, for example...). Figure 80 Therefore, the through holes and support posts are spaced apart by the same width to provide the correct alignment required to form a slidable engagement between them. The housing is thus slidably mounted on the support posts.

[0304] The housing 710 of the cleaning device can slide vertically up and down along a pair of support posts 210-4 to horizontally align the brush with the anode needle 205 and the cathode tube 203. When properly aligned, the brush centerline axis Bc defined by the brush handle 743 is preferably substantially vertically aligned with the gap formed between the anode needle 205 and the cathode tube 203 in the plasma chamber 202 to effectively remove residues / deposits formed on the anode needle and cathode tube (see, for example...). Figure 71The housing can be locked in one of several possible vertical positions along the support post. In one embodiment, to lock the housing relative to the anode needle and cathode tube in the desired vertical position on the support post 210-4, a locating screw 714 is provided from each of the mounting through holes 721 of the housing. The locating screws are rotatably mounted in mating threaded locating screw holes 713 that extend horizontally from the front portion 710c of the housing 710 to the through hole (see, for example...). Figure 74 and Figure 80 The screw shanks are rigidly engaged with their respective support posts and sufficient force is applied to hold the housing in place on the support posts; the housing is cantilevered and supported by the support posts. In some embodiments, the support posts 210-4 may be formed of a softer metal (such as aluminum) to allow the ends of the positioning screw shanks to slightly deform the support post material for better frictional engagement, in order to hold the housing 710 in place on the support posts.

[0305] The method or process of aligning the plasma torch cleaning device 700 with the plasma torch 201 typically involves slidably mounting the housing 710 of the plasma torch cleaning device 700 onto the support column 210-4, as described above. The housing 710 is then vertically adjusted on the support column to align the brush 740 horizontally with the anode needle 205 and cathode tube 203, such that when the plasma torch cleaning device 700 is actuated, the brush slidably engages with these elements of the plasma torch 201 and rubs / brushes them with a strong scrubbing action, as further described herein. The brush functions to mechanically remove ablation residues and deposits resulting from the excitation of plasma from the sample fluid. Once a suitable vertical position is found for the plasma torch cleaning device 700, the positioning screw 714 is tightened to rigidly engage the support column 210-4, thereby securing the housing 710 in the desired vertical position on the plasma torch assembly 200. In the non-limiting embodiment shown, the housing 710 is cantilevered by the support column 210-4 without any additional support from any additional mounting brackets or supports for rigidly connecting the housing to the plasma torch apparatus 200. That would impede the ability of the cleaning equipment housing to move freely up and down and to adjust vertically on the plasma torch apparatus to achieve proper alignment with the plasma torch. The locating screw 714 may optionally be loosely installed in its mating locating screw through hole 721 before or after mounting the housing 710 onto the support column 210-4 of the plasma torch apparatus body 210-1.

[0306] The cleaning device housing 710 can be mounted on any suitable side of the plasma torch device body 210-1. For example, in Figures 68-71In the illustrated embodiment, the cleaning device housing is mounted on the front of the main body, directly facing the spectrometer 300. In an alternative embodiment, the cleaning device housing may be mounted on either of the two lateral sides of the main body 210-1 at approximately a 90-degree angle to the spectrometer, such as... Figure 83 As shown (alternative mounting locations for the housing are indicated by dashed lines and marked 710'). The cleaning equipment can effectively clean the plasma torch 201 (e.g., anode needle 205 and cathode tube 203) from any of the aforementioned mounting locations, provided that brush 740 can access and engage the plasma torch elements.

[0307] To support and guide the brush holder 730 carrying the brush 740 during movement between the retracted and extended positions, the cleaning device housing 710 may include a pair of horizontally elongated guide rails 750 arranged on each side of the brush holder. Two pairs of guide rails 750 may be provided (e.g., one pair on each side); one pair of guide rails is arranged on each side of the actuation axis AA. The guide rails 750 project forward axially from the front end 710c of the housing 710 along and parallel to the actuation axis AA defined by the operating lever 722 of the actuator 720. The guide rails are preferably linearly straight, terminating at a free end 753b. Opposite fixed ends 753a are rigidly attached to the front end of the housing.

[0308] Each pair of guide rails 750 includes an upper guide rail 750a and a lower guide rail 750b, which are vertically spaced apart by a gap G1, said gap G1 being sized to slidably receive a guide protrusion 752 disposed on the brush holder 730 (see, for example...). Figure 74-80 (If applicable). Guide protrusions are formed on each side of the brush holder 730e and extend horizontally outward in opposite directions from the brush holder as shown to enter a corresponding gap G1 between a pair of guide rails. The guide protrusions 752 can have any suitable shape. For example, in the non-limiting embodiment shown, the guide protrusions are block-shaped (e.g., rectangular cuboids) with flat upper and lower surfaces for slidable engagement with the guide rails 750. Other suitable polygonal or non-polygonal shapes (e.g., circles) can also be used.

[0309] In the retracted position of brush 740 and brush holder 730, the guide protrusion 752 on the brush holder can be positioned proximal to and / or abutting against the front end 710c (e.g., front) of the cleaning device housing 710 (see example...). Figure 79 In the extended position of the brush and brush holder, the guide protrusion is horizontally spaced from the front end of the housing and located distal to the front end of the housing (see, for example...). Figure 80 ).

[0310] Any suitable shape can be provided for the preferably straight guide rail 750. For example, in the illustrated non-limiting embodiment, the guide rail is shaped as a cylindrical rod or pin, with its fixed end 753a rigidly connected to the housing 710. In one embodiment, the guide rail 750 can be retracted into a mating guide rail mounting hole 713 formed in the front of the housing defined by the front end 710c (see, for example...). Figure 74 In other embodiments, the guide rail can be secured to the housing from the inside of the housing using threaded fasteners by inserting threaded fasteners into the mounting holes 713. In other embodiments where the housing 710 is formed of a metal such as aluminum or steel, the guide rail can be welded to the housing at its fixed end 753a. Therefore, any suitable method for securing the guide rail to the cleaning equipment housing can be used.

[0311] A method for cleaning a plasma torch 201 of a plasma torch apparatus 200, operable to generate plasma from a sample fluid, will now be briefly outlined based on the foregoing description. The method includes mounting a housing 710 of a cleaning device 700 onto the plasma torch apparatus 200; the cleaning device includes an actuator 720 previously described herein, the actuator including a retractable operating lever 722 coupled to a pair of brushes 740 via a brush holder 730. The brushes include cleaning elements (e.g., bristles 742 or other types of cleaning elements).

[0312] The method continues by activating actuator 720 (i.e., extending operating lever 722), causing a pair of brushes 740 to move from the retracted position (see, for example, see...). Figure 70 and Figure 79 Move to the extended position (for example, see...) Figure 71 and Figure 80 During movement in the first direction, the cleaning elements of the brush slidably engage the anode and cathode (e.g., anode needle 205 and cathode tube 203) of the plasma torch 201. The method continues, and then, by activating an actuator (i.e., retraction lever 722), the pair of brushes return to the retracted position in the opposite second direction. As previously described herein, both the extension and retraction movements are essentially linear. The cleaning elements are configured and operable to remove deposits / residues formed on the anode and cathode by arousing sample fluid via a forceful brushing / wiping action. This effectively removes deposits / residues from at least a majority of the exposed surfaces of the anode needle 205 and cathode tube 203, which are prone to deposit / residue formation. Preferably, relatively stiff bristles, such as metal bristles (e.g., stainless steel, brass, or other materials), facilitate the desired forceful brushing action. Notably, both the extension and retraction movements along the anode and cathode in opposite directions, whether the brush travels outward or inward, effectively wipe a large portion of the anode and cathode surfaces.

[0313] It is worth noting that, such as Figures 70-71 As shown, the anode needle 205 and cathode tube 203 are vertically aligned along the torch centerline axis Tc. The brush 740 of the cleaning device 700 travels along a linear path between a retracted position and an extended position along an actuation axis AA defined by an actuator 720, which is transverse to (e.g., perpendicular to) the torch centerline axis.

[0314] The plasma torch cleaning process described above can be performed once after each sample passes through the plasma torch apparatus 200 (i.e., a single brush extension / retraction cycle) to capture spectral data from the plasma via a spectrometer 300 that analyzes the sample fluid for the analyte of interest, as previously described herein. Alternatively, in some embodiments, the cleaning process can be repeated continuously and rapidly several times during a single plasma torch cleaning operation (i.e., multiple brush extension / retraction cycles) to ensure that the anode needle 205 and cathode tube 203 are as clean as possible in cases where a single extension / retraction cycle of brush 740 may be insufficient to clean the plasma torch due to stubborn deposits / residues.

[0315] It should be noted that, in order to clearly describe other components of the cleaning equipment, any fasteners described herein may not be shown in all the figures.

[0316] Figures 84-95 An alternative flanged housing 760 for the plasma torch cleaning device 700 is depicted. In this embodiment, the housing 760 is configured to at least partially enclose the movable brush assembly (i.e., the brush holder 730 and the brush 740) and the fixed guide rail 750. This embodiment of the housing is useful in cases where the plasma chamber 202 can be enclosed by adding side panels 770 to the plasma torch device body 210-1 (see, for example, [link to relevant documentation]). Figure 94 This contrasts with the housing 710 of the cleaning device described earlier in this article, which has a substantially open side where the brush holder, brush, and guide rail are fully exposed.

[0317] The housing 760 includes a generally cup-shaped brush enclosure 761 that defines an inwardly / forwardly open cavity 764 facing the plasma torch 201 when the housing is mounted to the plasma torch assembly body 210-1. The brush enclosure 761 includes multiple sidewalls 768, a rear wall 767, and an open front end 763 extending through a mounting flange 762 to access the cavity. As shown, the sidewalls 768 extend 360 degrees around the enclosure. Sidewalls of any suitable shape can be used. The front end 763 terminates at the mounting flange 762, which is configured to engage at an opening 771 in a panel of the enclosure with one of the side panels 770 of the plasma torch assembly body 210-1, allowing the brush assembly to enter the processing chamber 202 through the opening 771 in the plasma torch assembly panel 770. Mounting flange 762 extends outward at a 90-degree angle from the front end 763 of the cup-shaped portion of housing 760 and extends 360 degrees around the front end 763. Sealing gasket 765 provides an airtight seal between mounting flange 762 and housing 770, completely surrounding opening 771. The opening 766 included in the sealing gasket is configured to complement the opening of the open front end 763 and the mating opening 771 on the side housing. Mounting flange 762 is mounted to housing 762 by threaded fastener 762a, which is received through corresponding concentrically aligned fastener holes 762b and 762c formed in the mounting flange and gasket. For clarity, Figure 86 The image shows only one of the four fasteners 762a used to mount the flange.

[0318] The brush enclosure 761, including the mounting flange 762, can be formed of metal and, in one embodiment as shown, can have an integral, one-piece structure, wherein the flange is an integral part of the brush enclosure. In some embodiments, a suitable metal may be aluminum or steel. In other embodiments, the mounting flange may be welded to the metal enclosure. Non-metallic enclosures, such as those formed of plastic, may also be used if conditions permit.

[0319] The rear wall 767 of the housing enclosure 761 includes a plurality of openings. These openings are substantially the same as those formed in the housing 710 previously described herein, but are located on the rear wall of this housing enclosure 761 instead of the front wall. For example, an actuator 720 is mounted to the rear wall 767 and cantilevered from the rear wall via a threaded fastener 729 received through a hole 715 in the rear wall. Four guide rail mounting holes 751 are formed in the rear wall 767 for cantilevering guide rails thereto in a similar manner to that previously described herein. The rear end portions of the guide rails are disposed inside the cavity 764. As shown, the front end portions of the guide rails project forward from the cavity and are disposed / exposed outside the cavity 764. The operating lever 722 of the actuator 720 extends forward through an opening 769 located at the center of the rear wall 767 for coupling to the brush holder 730 via a threaded fastener 727 in the same manner as previously described herein. When the operating lever 722 retracts into the cavity 764 or extends forward to actuate the brush holder and brush assembly and cause the brush holder and brush assembly to translate linearly to clean the plasma torch, the operating lever 722 can move linearly through the cavity 764 in the opposite direction.

[0320] The brush holder 730 and brush 740 assembly, coupled to the operating lever 722 of the linear actuator 720, are the same as previously described herein, including a guide protrusion 752 that slidably engages the guide rail 750. However, in this embodiment of the housing, the brush head 741 of the brush 740, which contains bristles, is partially retractable into the cavity 764 of the housing enclosure 760 when in the retracted position (see, for example...). Figure 91 When in the extended position engaged with the anode needle 205 and cathode tube 203 of the plasma torch 201, most of the brush head is positioned outside the cavity; in some embodiments, the entire brush head can be removed from the cavity and fully exposed (see, for example, see...). Figure 92 ).

[0321] The operation of the plasma torch cleaning device 700 with the housing 760 for cleaning the plasma torch is the same as that previously described herein. Therefore, the alternative housing with the brush enclosure 761 does not change the function of the cleaning device.

[0322] The system for agricultural sample analysis disclosed herein can be used with and can be incorporated into a holistic agricultural sampling and analysis system, such as, but not limited to, the systems described in the following U.S. patent applications: US2018 / 0124992A1, US20210123836A1, US20210123936A1, US20210131917A1, and US20210131929A. 1. US20210208035A1, US20210208036A1, US20210208037A1, US20210208123A1, US20210268456A1, US2 0210285869A1, US20210341442A1, US20210341452A1, US20220196628A1, US20230133335A1, US2023014 4670A1, US20230151810A1, US20230173415A1, US20230243792A1, US20230243801A1, US20230243802A 1. US20230243804A1, US20230266289A1, US20230266290A1, US20230273130A1, US20230273171A1, US20 230273172A1, US20230273173A1, US20230304987A1, US20230417363A1, US20230417635A1, US20240189 743A1, US20240189744A1, US20240192112A1, US20240192708A1, US20240198331A1, US20240200547A1,PCT announcements WO2021 / 171120, WO2021 / 171121, WO2022 / 243792, WO2022 / 243797, WO2022 / 243806, WO2022 / 243807, WO2022 / 243809, WO2022 / 259071, WO2022 / 259073, WO2022 / 259074, WO2023 / 031725, WO2023 / 031726, WO2023 / 031727, WO2023 / 042032, WO2023 / 042033, WO2023 / 0420 35, WO2023 / 042036, WO2023 / 042037, WO2023 / 042038, WO2023 / 042039, WO2023 / 161727, WO2023 / 161728, WO2023 / 170480, WO2023 / 17048 2, WO2023 / 227959, WO2023 / 227960, WO2023 / 248015, WO2023 / 248016, WO2024 / 023728, WO2024 / 023729, WO2024 / 023730 and WO2024 / 023731,PCT applications PCT / IB2024 / 051283 and PCT / IB2024 / 051820 filed on February 12, 2024; U.S. patent applications 63 / 551120 filed on February 8, 2024; 63 / 552730, 63 / 552739, and 63 / 559305, 63 / 559308, and 63 / 559312 filed on February 29, 2024; and 202... The following are submissions dated February 29, 2023: 63 / 559316, 63 / 586486, 63 / 586489, 63 / 586497, 63 / 586500, 63 / 586504, 63 / 586510, 63 / 586514, 63 / 586524, and 63 / 586524. Submissions 63 / 586529, 63 / 586545, 63 / 586551, 63 / 586555, 63 / 586562, 63 / 586608, 63 / 586619, 63 / 586630, 63 / 586638, and 63 / 586638 submitted on September 29, 2023. The following are subject to change: 86656, 63 / 586672 (submitted September 29, 2023), 63 / 586702 (submitted September 29, 2023), 63 / 586726 (submitted September 29, 2023); 63 / 586955, 63 / 586966, 63 / 586978, 63 / 586984, 63 / 586990 (submitted September 29, 2023), and 63 / 646070 (submitted May 13, 2023).

[0323] Example

[0324] The following are non-restrictive examples.

[0325] Example 1 - A sample analysis device comprising: a mixing pump, the mixing pump including: a pump body defining a pumping chamber; and an elastically deformable diaphragm disposed within the pumping chamber, the diaphragm being deformable and operable to pump sample fluid out of the pumping chamber; the mixing pump further comprising a positive displacement pump incorporated in the pump body, the positive displacement pump including a pump orifice formed in the pump body, the pump orifice containing a pilot fluid and fluidly connected to the pumping chamber, the positive displacement pump being operable to actuate the diaphragm via displacement of the pilot fluid acting on the diaphragm; etc. A plasma torch apparatus comprising a plasma chamber and a plasma torch at least partially disposed within the plasma chamber, the plasma torch being fluidly coupled to a mixing pump and configured to receive and discharge a flow of sample fluid from the mixing pump; the plasma torch being configured to be connected to a power source; and a spectrometer having a line of sight into the plasma chamber; wherein the spectrometer is operable to detect analytes of interest in the sample fluid discharged by the plasma torch as the sample fluid is vaporized by energizing the plasma torch to form a plasma.

[0326] Example 2 - The sample analysis apparatus according to Example 1 further includes a central manifold block fluidly connected between the plasma torch apparatus and the mixing pump, the central manifold block defining a flow path for fluidly connecting the mixing pump to the plasma torch.

[0327] Example 3 - The sample analysis device according to Example 2, wherein the central manifold block defines a flat side that abuts against a mating flat side of the pump body, and the pumping cavity is recessed into the mating flat side of the pump body.

[0328] Example 4 - A sample analysis apparatus according to Example 3, wherein the pumping chamber includes a concave surface facing the central manifold block.

[0329] Example 5 - A sample analysis apparatus according to Example 4, wherein the flat side of the central manifold block seals the pumping chamber, and the diaphragm is disposed between the flat side and the concave surface of the central manifold block.

[0330] Example 6 - A sample analysis apparatus according to any one of Examples 2-5, wherein the central manifold block includes fluid passages defining the pump inlet and pump outlet of the mixing pump.

[0331] Example 7 - A sample analysis apparatus according to any one of Examples 1-6, wherein the plasma torch comprises: an anode needle, the end of which is disposed in the plasma chamber; and a cathode tube, the open end of which is disposed in the plasma chamber and spaced apart from the end of the anode needle, the cathode tube being fluidly connected to the pumping chamber to discharge the sample fluid into the plasma chamber.

[0332] Example 8 - A sample analysis apparatus according to Example 7, wherein the anode needle is electrically connected to the power source and the cathode tube is electrically connected to ground, and wherein, when the plasma torch apparatus is energized, the plasma is formed between the anode needle and the cathode tube.

[0333] Example 9 - A sample analysis apparatus according to Example 1, wherein the spectrometer includes an optical element comprising a lens, the optical element being at least partially inserted through the housing of the plasma torch and into an optical channel formed in the plasma chamber, and operable to receive light emitted by the plasma.

[0334] Example 10 - A sample analysis apparatus according to Example 9, wherein the housing of the plasma torch device includes a lens defogging feature, the lens defogging feature including an airflow duct connected to a pressurized air source and configured to blow air through the lens to prevent fogging.

[0335] Example 11 - A sample analysis apparatus according to Example 9 or 10, wherein the spectrometer is configured to analyze the light to determine the amount of analytes comprising plant nutrients of agricultural concern in the sample fluid.

[0336] Example 12 - The sample analysis apparatus according to Example 10, wherein the plant nutrients are selected from the group consisting of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, zinc, manganese, copper, boron, molybdenum and chlorine.

[0337] Example 13 - A sample analysis apparatus according to any one of Examples 9 to 12, wherein the spectrometer is supported by the housing of the plasma torch device.

[0338] Example 14 - A sample analysis apparatus according to Example 1, wherein the pump orifice of the positive displacement pump is integrally formed in the pump body of the mixing pump.

[0339] Example 15 - A sample analysis apparatus according to Example 14, wherein the positive displacement pump is an injection pump, the injection pump including a pump piston slidably disposed in the pump orifice, the pump piston being movable in opposite directions to draw the pilot fluid from the pumping chamber of the mixing pump and pump the pilot fluid into the pumping chamber for pumping sample fluid.

[0340] Example 16 - The sample analysis apparatus according to Example 15 further includes a pilot fluid crossflow channel integrally formed in the pump body of the mixing pump, the pilot fluid crossflow channel fluidly connecting the pump orifice to the pumping chamber of the mixing pump.

[0341] Example 17 - A sample analysis apparatus according to Example 16, wherein the injection pump includes a pressure relief device comprising: a pressure relief orifice integrally formed in the pump body of the sample pump, the pressure relief orifice being fluidly connected to the pilot fluid flow channel via the pilot fluid crossflow channel; and a pressure relief piston slidably disposed within the pressure relief orifice.

[0342] Example 18 - The sample analysis apparatus according to Example 17 further includes a pressure relief spring disposed in the pressure relief orifice, the pressure relief spring acting on the pressure relief piston to set the pressure relief pressure for the pilot fluid.

[0343] Example 19 - A sample analysis apparatus according to any one of Examples 15-18, the sample analysis apparatus further comprising an actuator operatively coupled to the pump piston, the actuator being configured to move the pump piston in the opposite direction.

[0344] Example 20 - A sample analysis apparatus according to any one of Examples 1-20, wherein the pilot fluid is hydraulic oil.

[0345] Example 21 - A sample analysis apparatus according to any one of Examples 1-20, wherein the sample fluid comprises a slurry formed from a mixture of water and soil.

[0346] Example 22 - A sample analysis apparatus according to any one of Examples 1-22, the apparatus further comprising a pressure sensor operable to measure the pilot fluid pressure.

[0347] Example 23 - The sample analysis apparatus according to Example 1 further includes an air removal device fluidly coupled to the pilot fluid, the air removal device being configured and operable to extract air from the pilot fluid.

[0348] Example 24 - A sample analysis apparatus according to Example 23, wherein the air removal device includes a housing containing an air-permeable membrane, thereby forming a transportable gas interface between the pilot fluid on a first side of the air-permeable membrane and a vacuum applied to a second side of the air-permeable membrane by a vacuum source.

[0349] Example 25 - A sample analysis apparatus according to Example 23, wherein the air-permeable membrane is disposed in a receiver formed in the housing, the receiver including a plurality of airflow through openings that are in fluid communication with the pilot fluid through the air-permeable membrane.

[0350] Example 26 - A sample analysis apparatus according to Example 24 or 25, wherein the housing is connected to the pump body and includes: an air inlet located on a first side of the permeable membrane and fluidly connected to an internal flow channel in the pump body containing the pilot fluid; and an air outlet located on a second side of the permeable membrane and fluidly connected to the vacuum source.

[0351] Example 27 - A sample analysis apparatus according to any one of Examples 24-26, wherein the air-permeable membrane is formed of silicone rubber.

[0352] Example 28 - A mixing pump comprising: a pump body defining a pumping chamber; a resiliently deformable diaphragm disposed in the pumping chamber, the diaphragm defining a pilot side and an operating side, the operating side configured to contact a process fluid to be pumped; a pump orifice formed in the pump body and containing a pilot fluid, the pump orifice being fluidly connected to the pumping chamber; a piston slidably disposed in the pump orifice and acting on the pilot fluid; and an actuator coupled to the piston, the actuator being operable to: move the piston in a first direction to push the pilot fluid toward the pumping chamber, causing the diaphragm to move toward the operating side to pump the process fluid; and move the piston in an opposite second direction to pull the pilot fluid back from the pumping chamber, allowing the diaphragm to move back toward the pilot side to fill the pumping chamber with the process fluid.

[0353] Example 29 - A mixing pump according to Example 28, wherein the pumping chamber is formed on the outer surface of the pump body and opens outward from the outer surface.

[0354] Example 30 - A mixing pump according to Example 29, wherein the pumping chamber has a concave shape defined by the arcuate curved wall of the pump body.

[0355] Example 31 - A mixing pump according to Example 30, wherein the pumping chamber includes a plurality of anti-jamming grooves recessed in the arcuate curved wall of the pump body.

[0356] Example 32 - A mixing pump according to Example 29 or 30, the mixing pump further comprising a manifold block connected to the pump body and surrounding the pumping chamber.

[0357] Example 33 - A mixing pump according to Example 32, wherein the diaphragm is trapped between the manifold block and the pump body.

[0358] Example 34 - A mixing pump according to Example 32 or 33, wherein the manifold block defines a fluid inlet port and a fluid outlet port.

[0359] Example 35 - A mixing pump according to Example 34, wherein the fluid inlet port and the fluid outlet port penetrate a pumping recess formed on the outer surface of the manifold block, the pumping recess facing the working side of the diaphragm to enclose the pumping chamber.

[0360] Example 36 - A mixing pump according to Example 35, wherein the pumping recess includes a flat wall.

[0361] Example 37 - A mixing pump according to Example 36, wherein the flat wall includes a plurality of anti-jamming grooves recessed into the flat wall.

[0362] Example 38 - A mixing pump according to any one of Examples 34 to 37, wherein the fluid outlet port is located in the central region of the pumping recess and the fluid inlet port is located in the first end region of the pumping recess.

[0363] Example 39 - The mixing pump according to Example 38 further includes a third fluid port located in a second end region of the pumping recess opposite to the first end region.

[0364] Example 40 - A mixing pump according to any one of Examples 28-39, wherein the pumping chamber and the diaphragm are vertically oriented.

[0365] Example 41 - A mixing pump according to any one of Examples 28-40, wherein the pump body further includes a pressure relief device comprising: a pressure relief orifice integrally formed in the pump body and in fluid communication with the pump orifice; and a pressure relief piston slidably disposed in the pressure relief orifice.

[0366] Example 42 - According to the mixing pump of Example 41, the mixing pump further includes a pressure relief spring disposed in the pressure relief orifice, the pressure relief spring acting on the pressure relief piston to set the pressure relief pressure for the pilot fluid.

[0367] Example 43 - The mixing pump according to Example 41 or 42 further includes a pilot fluid flow channel integrally formed in the pump body, the pilot fluid flow channel fluidly connecting the pump orifice and the pressure relief orifice to the pumping chamber.

[0368] Example 44 - A mixing pump according to any one of Examples 28-43, wherein the pilot fluid is hydraulic oil or water.

[0369] Example 45 - A mixing pump according to Example 28, wherein the pump body has a polygonal configuration.

[0370] Example 46 - A mixing pump according to Example 28, wherein the actuator is a linear actuator.

[0371] Example 47 - A mixing pump according to any one of Examples 28-46, wherein the process fluid is an agricultural sample slurry.

[0372] Example 48 - A sample analysis system comprising: a plasma torch apparatus including a plasma chamber and a plasma torch at least partially disposed within the plasma chamber, the plasma torch including an anode and a cathode, at least one of the anode and the cathode being configured to receive a sample fluid and dispense the sample fluid into the plasma chamber; the plasma torch being configured to be connected to a power source, and when energized, the plasma torch being operable to generate plasma from the sample fluid in a gap between the anode and the cathode; and a spectrometer having a line of sight into the plasma chamber, the spectrometer being configured to collect light emitted by the plasma. The system measures the analytes in the sample fluid; it includes a plurality of diaphragm pumps, each diaphragm pump comprising a pump body defining a pumping chamber controlled by an elastically deformable diaphragm; and a corresponding manifold block encloses the pumping chamber and includes a plurality of flow channels integrally formed in the manifold block and in fluid communication with the pumping chamber; a mixing manifold block including a plurality of flow channels integrally formed in the mixing manifold block and in fluid communication with the manifold block of the diaphragm pump, the flow channels of the mixing manifold block including a main flow channel in fluid communication with the plasma torch; wherein the main flow channel is configured to collect process fluid comprising the sample fluid from the diaphragm pump and deliver the process fluid to the plasma torch.

[0373] Example 49 - A sample analysis system according to Example 48, wherein each pump body further includes an integrally formed injection pump containing a pilot fluid, each injection pump being operable to actuate a corresponding diaphragm in the diaphragms via displacement of the pilot fluid to fill the pumping chamber with the process fluid and pump the process fluid out of the pumping chamber.

[0374] Example 50 - A sample analysis system according to Example 49, wherein each pump body further includes a pressure relief device comprising: a pressure relief orifice integrally formed in the pump body and in fluid communication with the pump orifice; and a spring-biased pressure relief piston slidably disposed in the pressure relief orifice.

[0375] Example 51 - A sample analysis system according to Example 49 or 50, wherein the pilot fluid is oil or water.

[0376] Example 52 - A sample analysis system according to any one of Examples 48 to 51, wherein the diaphragm pumps are physically coupled together to form a single self-supporting housing supporting the plasma torch device.

[0377] Example 53 - A sample analysis system according to Example 52, wherein the mixing manifold block is abuttingly connected to the body of the plasma torch device, and each of the manifold blocks of the diaphragm pump is abuttingly connected to the corresponding outer surface of the mixing manifold block.

[0378] Example 54 - A sample analysis system according to any one of Examples 48-53, wherein the diaphragm pump comprises: a standard pump operable to pump a standard solution to the plasma torch via the mixing manifold; a diluent pump operable to pump a diluent to the plasma torch via the mixing manifold; and a sample pump operable to pump the sample fluid to the plasma torch via the mixing manifold.

[0379] Example 55 - A sample analysis system according to Example 54, wherein a portion of the main flow channel defines a branch mixing zone that collects sample fluid, standard solution, and diluent.

[0380] Example 56 - A sample analysis system according to Example 55, wherein the distance between the branched mixing zone and the gap between the anode tube and the cathode tube is no more than three inches.

[0381] Example 57 - A sample analysis system according to any one of Examples 54-56, wherein the sample pump is fluidly connected to an extractant source, and the diaphragm pump further includes a mixing pump fluidly connected to the sample pump, the mixing pump being configured such that the agricultural sample slurry moves back and forth between the mixing pump and the sample pump to mix the extractant with the sample fluid.

[0382] Example 58 - A method for assembling an agricultural sample analysis device, the method comprising: abutting together a plurality of mixing pumps to form a structurally self-supporting housing, each of the mixing pumps comprising: a pump body including an integrated syringe pump containing a pilot fluid; a pumping chamber including an elastically deformable diaphragm fluidly connected to the syringe pump; and a manifold block enclosing the pumping chamber and including a plurality of internal flow channels integrally formed therein and fluidly communicating with the pumping chamber; mounting a plasma torch device to the housing, the plasma torch device including an energized plasma torch defining fluid channels configured to dispense process fluids and excite process fluids to form plasma; and coupling a spectrometer to the plasma torch device, the spectrometer having a line of sight into the plasma torch and configured to measure analytes in the process fluids.

[0383] Example 59 - The method according to Example 58 further includes fluidly interconnecting each of the manifold blocks to a mixing manifold block, the mixing manifold block including a plurality of internal flow channels in fluid communication with the flow channels of the manifold block of the mixing pump.

[0384] Example 60 - The method according to Example 59, wherein the mixing manifold block is centrally positioned in the housing and engages with the manifold block of each of the mixing pumps.

[0385] Example 61 - The method according to Example 59 or 60, wherein the mixing manifold block is engaged with the plasma torch device.

[0386] Example 62 - A method according to any one of Examples 59 to 61, wherein the installation step includes fluidly connecting the main flow channel of the mixing manifold block to the plasma torch.

[0387] Example 63 - The method according to Example 56, wherein the main flow channel includes a mixing zone configured to receive and mix process fluids from each of the manifold blocks and to deliver the mixture of process fluids to the plasma torch.

[0388] Example 64 - The method according to Example 63, wherein the gap formed between the mixing zone and the anode needle and cathode tube of the plasma torch is no more than three inches.

[0389] Example 65 - A method according to any one of Examples 59-64, wherein the mixing pump comprises: an agricultural sample pump fluidly connected to an agricultural sample fluid source; a diluent pump fluidly connected to a diluent source; and a standard pump fluidly connected to a standard solution source containing a known amount of an analyte of agricultural interest.

[0390] Example 66 - The method according to Example 65, wherein the mixing pump further includes a mixing pump fluidly connected to the sample pump, and the mixing pump is fluidly connected to the mixing manifold block only through the sample pump.

[0391] Example 67 - A method for processing a sample, the method comprising: providing a sample analysis apparatus including a plasma torch device and a cluster of pumps, the pumps being in fluid communication with a plasma torch of the plasma torch device, the plasma torch being operable to generate plasma; filling a first mixing pump in the cluster of mixing pumps with a first process fluid derived from an agricultural sample; filling a second mixing pump in the cluster of mixing pumps with a second process fluid; discharging and mixing the first process fluid and the second process fluid, respectively, from the first mixing pump and the second mixing pump, to form a combined flow toward the plasma torch; and changing the respective flow rate from each of the first mixing pump and the second mixing pump to achieve a specific ratio of the first process fluid and the second process fluid in the combined flow toward the plasma torch.

[0392] Example 68 - The method according to Example 67 further includes: exciting a combined flow rate of the first process fluid and the second process fluid by energizing the plasma torch, and performing spectral analysis of the plasma using a spectrometer to measure analytes of agricultural interest.

[0393] Example 69 - The method according to Example 67 or 68, wherein the first process fluid and the second process fluid are selected from the group consisting of sample slurry, diluent and standard solution.

[0394] Example 70 - A method according to any one of Examples 67-69, the method further comprising: filling a third mixing pump in the cluster of mixing pumps with a third process fluid different from the first and second process fluids, and mixing the third process fluid from the third mixing pump with the combined flow from the first and second mixing pumps and discharging it to the plasma torch.

[0395] Example 71 - The method according to Example 70 further includes changing the flow rate of each of the first mixing pump, the second mixing pump, and the third mixing pump to achieve a specific ratio of the first process fluid, the second process fluid, and the third process fluid in the combined flow toward the plasma torch.

[0396] Example 72 - The method according to Example 71, wherein the first process fluid is a sample slurry, the second process fluid is a diluent, and the third process fluid is a standard solution.

[0397] Example 73 - The method according to any one of Examples 70-72, the method further comprising providing a programmable controller operatively coupled to the first mixing pump, the second mixing pump and the third mixing pump, wherein the controller is configured to automatically change the flow rates of the first mixing pump, the second mixing pump and the third mixing pump to achieve a specific ratio of the first process fluid, the second process fluid and the third process fluid in the combined flow.

[0398] Example 74 - A method according to any one of Examples 61-67, wherein the pump is a hybrid pump, each of the hybrid pumps comprising: a pump body including an integrated syringe pump containing a pilot fluid; a pumping chamber including an elastically deformable diaphragm operatively coupled to the syringe pump; and a manifold block encloses the pumping chamber and includes a plurality of internal flow channels integrally formed therein and in fluid communication with the pumping chamber.

[0399] Example 75 - A method according to any one of Examples 61-68, wherein the mixing pumps are structurally coupled together to form a common housing supporting the plasma torch device.

[0400] Example 76 - A method for processing a sample, the method comprising: providing a sample analysis apparatus including a plasma torch device and a cluster of mixing pumps, the mixing pumps being in fluid communication with a plasma torch of the plasma torch device, the plasma torch being configured to dispense fluid and generate plasma; filling a first mixing pump in the cluster of mixing pumps with a first process fluid; discharging the first process fluid from the first mixing pump to the plasma torch, the plasma torch dispensing the first process fluid; exciting the plasma formed by the first process fluid by energizing the plasma torch; filling a second mixing pump in the cluster of mixing pumps with a second process fluid; gradually reducing the flow rate of the first process fluid flowing to the plasma torch while gradually increasing the flow rate of the second process fluid discharged from the second mixing pump to the plasma torch to maintain a minimum flow rate to the plasma torch required to maintain a stable plasma.

[0401] Example 77 - The method according to Example 76, wherein the step of filling the second mixing pump is performed while the first process fluid is discharged from the first mixing pump to the plasma torch.

[0402] Example 78 - The method according to Example 76 or 77, wherein the operation of the first mixing pump and the second mixing pump is switched such that a continuous supply of the first process fluid or the second process fluid to the plasma torch is maintained to maintain a stable plasma.

[0403] Example 79 - A method according to any one of Examples 76-78, wherein the plasma torch includes a cathode and an anode, at least one of the cathode and the anode defining a fluid channel in fluid communication with the first mixing pump and the second mixing pump to receive and discharge the first process fluid and the second process fluid, and the plasma is formed in the gap between the anode and the cathode.

[0404] Example 80 - The method according to any one of Examples 76-79, the method further comprising collecting spectral information from the plasma using a spectrometer to measure an analyte of agricultural interest in the first process fluid.

[0405] Example 81 - A sample analysis apparatus comprising: a plasma torch assembly including a body defining a plasma chamber and a plasma torch supported by the body; the plasma torch including: an anode, one end of which is disposed in the plasma chamber and configured to be electrically connected to a power source; a cathode, one end of which is disposed in the plasma chamber and spaced apart from the one end of the anode by a gap, the cathode being configured to be electrically connected to ground; at least one of the anode or the cathode defining a longitudinal fluid passage configured to receive sample fluid and distribute the sample fluid into the gap; the plasma torch being operable to form plasma from the sample fluid in the gap when energized; and a spectrometer having a line of sight into the plasma chamber, the spectrometer being configured and operable to analyze the plasma to measure analytes of agricultural interest in the sample fluid.

[0406] Example 82 - A sample analysis apparatus according to Example 81, wherein the spectrometer includes a light-collecting tube disposed in a through channel formed in the rear wall of the body and entering the plasma chamber.

[0407] Example 83 - A sample analysis apparatus according to Example 82, wherein the light-collecting tube terminates at a lens, the lens being recessed within the through-channel and separated from the plasma chamber by a distance.

[0408] Example 84 - A sample analysis apparatus according to Example 83, wherein the light-collecting tube is located 1 to 4 inches from the centerline of the plasma torch defined by the anode and the cathode.

[0409] Example 85 - The sample analysis apparatus according to Example 83 or 84 further includes a cleaning device for cleaning the lens.

[0410] Example 86 - A sample analysis apparatus according to Example 85, wherein a cleaning device for cleaning the lens includes an air inlet channel formed in the body, the air inlet channel being in fluid communication with a portion of the through channel between the lens and the plasma chamber, the air inlet channel being configured to be connected to a pressurized air source and operable to blow airflow across a surface of the lens facing the plasma chamber.

[0411] Example 87 - A sample analysis apparatus according to Example 86, wherein air is heated.

[0412] Example 88 - The sample analysis apparatus according to Example 86 or 87 further includes a light-transmitting barrier formed between the lens and the plasma chamber.

[0413] Example 89 - A sample analysis apparatus according to Example 79, wherein the cleaning device for cleaning the lens includes a heater for heating the lens.

[0414] Example 90 - A sample analysis apparatus according to Example 85, wherein the cleaning device for cleaning the lens includes a mechanical wiping device comprising a wiping element movable across a surface of the lens facing the plasma chamber.

[0415] Example 91 - A sample analysis apparatus according to any one of Examples 81-90, wherein the spectrometer is supported by the main body of the plasma torch apparatus.

[0416] Example 92 - A sample analysis apparatus according to any one of Examples 81-84, wherein the body of the plasma torch includes a waste trough formed by a recess on the body located at the bottom of the plasma chamber, the waste trough being configured to collect excess sample fluid dispensed by the cathode.

[0417] Example 93 - The sample analysis apparatus according to Example 92 further includes a waste ditch formed on the bottom wall of the waste tank to collect the excess sample fluid and guide the excess sample fluid outward through an outlet opening formed in the body of the plasma torch apparatus.

[0418] Example 94 - A sample analysis apparatus according to Example 81, wherein the longitudinal fluid passage is configured to receive a conductive fluid and mix the conductive fluid with the sample fluid upstream of the gap.

[0419] Example 95 - A sample analysis apparatus according to Example 94, wherein the conductive fluid is an acid.

[0420] Example 96 - A sample analysis apparatus according to any one of Examples 81-95, wherein the sample fluid is a soil slurry comprising water and soil solids.

[0421] Example 97 - The sample analysis apparatus according to Example 81 further includes a filter located upstream of the plasma torch, the filter filtering the sample fluid.

[0422] Example 98 - A sealing system for pressure balancing of a pump, the sealing system comprising: a pump body and an operating piston, the pump body defining a pump orifice, the operating piston being slidably disposed within the pump orifice for movement in opposite axial directions; the operating piston defining a sealing interface with a wall of the pump orifice; a first pressure zone formed on a first side of the sealing interface; a second pressure zone formed on a second side of the sealing interface; a pilot fluid disposed on both the first and second sides of the sealing interface; wherein the second side of the sealing surface is fluidly connected to a pressure control device operable to adjust the pressure of the pilot fluid in the second pressure zone.

[0423] Example 99 - A sealing system according to Example 98, wherein the pressure control device is configured such that a second pressure of the pilot fluid generated in the second pressure zone is lower than a first pressure in the first pressure zone.

[0424] Example 100 - A sealing system according to Example 99, wherein the first pressure is a negative pressure and the second pressure is a negative pressure lower than the first pressure.

[0425] Example 101 - A sealing system according to any one of Examples 98-100, wherein the pressure control device is a vacuum pump.

[0426] Example 102 - A sealing system according to any one of Examples 98-101 further includes: a first sealing piston disposed within the pump orifice, the first sealing piston being coupled to the operating piston in a spaced-apart relationship to form a first piston assembly; and a pressure-balanced first intermediate chamber formed within the pump orifice between the operating piston and the first sealing piston, the first intermediate chamber defining a second pressure zone.

[0427] Example 103 - A sealing system according to Example 102, wherein the first intermediate chamber is movable together with the first piston assembly within the pump orifice in opposite axial directions.

[0428] Example 104 - A sealing system according to Example 102 or 103, the sealing system further comprising: a pressure relief port defined within the pump body; a second piston assembly slidably disposed within the pressure relief port for movement in opposite axial directions, the second piston assembly including a pressure relief piston spaced apart from a second sealing piston; a pressure-balanced second intermediate chamber formed within the pressure relief port and between the pressure relief piston and the second sealing piston, the second intermediate chamber defining a third pressure zone containing the pilot fluid; the first intermediate chamber of the first piston assembly being fluidly connected to the second intermediate chamber; wherein the third pressure zone is in fluid communication with the second pressure zone.

[0429] Example 105 - A sealing system according to Example 104, wherein the pressure in the third pressure zone is equal to the second pressure in the second pressure zone formed by the first intermediate chamber within the pump orifice.

[0430] Example 106 - The sealing system according to Example 104 or 105 further includes a pressure relief spring acting on the second piston assembly within the pressure relief orifice.

[0431] Example 107 - The sealing system according to Example 102 or 103 further includes a linear actuator coupled to the first piston assembly, the linear actuator being configured to move the first piston assembly in opposite axial directions.

[0432] Example 108 - The sealing system according to any one of Examples 98-107 further includes an elastically deformable diaphragm disposed at a pumping chamber formed in the body of a pump and containing a process fluid, the process fluid being in contact with the working side of the diaphragm, and the pumping chamber being fluidly connected to a first pressure zone containing a pilot fluid located on the pilot side of the diaphragm.

[0433] Example 109 - A sealing system according to Example 108, wherein moving the operating piston in the pump orifice in a first axial direction causes the diaphragm to pump the process fluid out of the pumping chamber; and moving the piston assembly in the opposite second axial direction causes the diaphragm to draw the process fluid into the pumping chamber on the working side of the diaphragm.

[0434] Example 110 - A sealing system according to any one of Examples 98-109, wherein the pilot fluid is oil.

[0435] Example 111 - A sealing system according to Example 107, wherein the operating piston and the pump orifice define a positive displacement injection pump.

[0436] Example 112 - A sealing system for pressure balancing of a positive displacement pump, the sealing system comprising: a sealing interface defined between a sealing member and a pump orifice, the sealing member being slidable within the pump orifice in opposite axial directions; a first pressure zone formed in the pump orifice on a first side of the sealing interface, the first pressure zone containing a first capture volume of pilot fluid operable to act on a displaceable pumping element; a second pressure zone formed in the pump orifice on a second side of the sealing interface, the second pressure zone containing a second capture volume of pilot fluid; the second pressure zone being fluidly connected to a pressure reducing device operable to reduce a second pressure of the pilot fluid in the second pressure zone to a pressure lower than the first pressure of the pilot fluid in the first pressure zone.

[0437] Example 113 - A sealing system according to Example 112, wherein the first pressure is a negative pressure and the second pressure is a negative pressure lower than the first pressure.

[0438] Example 114 - A sealing system according to Example 112 or 113, wherein the pressure reducing device is a vacuum pump.

[0439] Example 115 - A sealing system according to any one of Examples 112-114, wherein the pump orifice is integrally formed in the pump body, and the sealing member is an operating piston slidably disposed within the pump orifice.

[0440] Example 116 - A sealing system according to Example 115, wherein the operating piston is coupled to a linear actuator configured to move the operating piston in opposite linear directions.

[0441] Example 117 - A sealing system according to Example 115 or 116, wherein the operating piston is fixedly connected to a sealing piston in the pump orifice to form a pump assembly, and an intermediate chamber is formed in the pump orifice between the operating piston and the sealing piston, the intermediate chamber defining the second pressure zone.

[0442] Example 118 - An air removal system for a fluid, the air removal system comprising: an air removal device fluidly connected to a reservoir containing a liquid; the air removal device including an air-permeable membrane forming a transferable gas interface between a first side of the air-permeable membrane in contact with the liquid fluid and a second side exposed to a vacuum applied by a vacuum source; wherein the air-permeable membrane is configured to allow air entrained in the liquid to be drawn through the air-permeable membrane to the second side, while retaining the liquid on the first side.

[0443] Example 119 - An air removal system according to Example 118, wherein the air removal device includes a housing capable of being mechanically coupled to a fluid component body defining a reservoir containing the liquid.

[0444] Example 120 - An air removal system according to Example 119, wherein the housing includes a receiver disposed of the air-permeable membrane, the receiver being fluidly connected to the reservoir via an air inlet located on a first side of the air-permeable membrane, and fluidly connected to a vacuum source located on a second side of the air-permeable membrane.

[0445] Example 121 - An air removal system according to Example 120, wherein the receiver includes: a first wall located on a first side of the air-permeable membrane, the first wall including a plurality of first airflow through openings in fluid communication with the liquid; and a second wall facing the first wall, the second wall including a plurality of second airflow through openings located on a second side of the air-permeable membrane and in fluid communication with the vacuum source.

[0446] Example 122 - An air removal system according to any one of Examples 119-121, wherein the fluid component body defining the reservoir is part of a pump.

[0447] Example 123 - An air removal system according to Example 122, wherein the pump includes an elastically deformable diaphragm operable to pump a process fluid on a working side of the diaphragm, the fluid being a pilot fluid acting on a pilot side of the diaphragm to actuate the diaphragm.

[0448] Example 124 - An air removal system according to Example 123, wherein the piston acts on the pilot fluid, the piston is slidably disposed within a pump orifice and coupled to a linear actuator operable to move the piston to displace the pilot fluid and actuate the diaphragm.

[0449] Example 125 - An air removal system according to any one of Examples 119-124, wherein the air inlet is partially defined by a rod capable of being at least partially inserted into an opening of a flow channel in the fluid component body.

[0450] Example 126 - An air removal system according to any one of Examples 119-125, wherein the housing includes a first half-section detachably coupled to a mating second half-section, and the receiver is defined by the first half-section and the second half-section together.

[0451] Example 127 - An air removal system according to Example 126, wherein the housing is cylindrical.

[0452] Example 128 - An air removal system according to any one of Examples 118-127, wherein the air-permeable membrane is formed of silicone rubber.

[0453] Example 129 - A method for operating a plasma torch, the method comprising: increasing the flow of a process fluid through a hollow electrode of the plasma torch to a first flow rate; exciting a plasma from the process fluid by energizing the hollow electrode; reducing the flow of the process fluid to a second flow rate lower than the first flow rate; and measuring an analyte of interest in the process fluid at the second flow rate.

[0454] Example 130 - The method according to Example 129, wherein the process fluid comprises a sample fluid containing the analyte of interest.

[0455] Example 131 - The method according to Example 129 or 130, wherein the sample fluid is a soil slurry.

[0456] Example 132 - The method according to any one of Examples 129-131, wherein the analyte is measured via a spectrometer.

[0457] Example 201 - A sample analysis apparatus comprising: a plasma torch apparatus including a plasma chamber and a plasma torch at least partially disposed within the plasma chamber; the plasma torch being configured to be connected to a power source; and a spectrometer having a line of sight into the plasma chamber; wherein the spectrometer is operable to detect an analyte of interest in the sample fluid when plasma is formed by vaporizing a sample fluid emitted by the plasma torch via energizing the plasma torch; wherein the plasma torch apparatus includes: a first electrode having a needle and a second electrode having a tube; the first electrode being electrically connected to a first electrical connector, and the second electrode being electrically connected to a second electrical connector, the first and second electrical connectors being connected to the power source; wherein the first electrode is adjustable within the plasma torch apparatus to adjust the electrode gap between the first and second electrodes.

[0458] Example 202 - A sample analysis apparatus according to Example 201, wherein the line of sight of the spectrometer passes through a light-collecting tube, and the spectrometer further includes a heating element disposed adjacent to the light-collecting tube, the heating element being configured to provide sufficient heating to the plasma torch device to be above the dew point temperature of water.

[0459] Example 203 - A sample analysis apparatus according to Example 201 or Example 202, wherein the first electrode has a deflector connected to a needle at the bottom of the first electrode, and the deflector is parabolic in shape.

[0460] Example 204 - A sample analysis apparatus according to any one of Examples 201 to 203, the sample analysis apparatus further comprising a fan connected to the plasma torch apparatus for providing a vacuum or positive pressure to the plasma chamber.

[0461] Example 205 - A sample analysis apparatus according to Example 204, wherein the fan provides a vacuum.

[0462] Example 206 - A sample analysis apparatus according to any one of Examples 201 to 205, the sample analysis apparatus further comprising a fluid retention section disposed in a plasma chamber and extending through the plasma torch apparatus to allow fluid to be discharged from the plasma chamber.

[0463] Example 207 - A sample analysis apparatus according to Example 206, wherein the fluid retention section has an inlet, and the inlet is located above the bottom of the plasma chamber.

[0464] Example 208 - A sample analysis apparatus comprising: a plasma torch apparatus including a plasma chamber and a plasma torch at least partially disposed within the plasma chamber; the plasma torch being configured to be connected to a power source; a spectrometer having a line of sight entering the plasma chamber through a light-collecting tube disposed through the plasma torch apparatus; and a heating element disposed adjacent to the light-collecting tube, the heating element being configured to provide sufficient heating to the plasma torch apparatus to be above the dew point temperature of water; wherein the spectrometer is operable to detect an analyte of interest in the sample fluid when the sample fluid emitted from the plasma torch is vaporized by energizing the plasma torch to form plasma.

[0465] Example 209 - A sample analysis apparatus comprising: a plasma torch apparatus including a plasma chamber and a plasma torch at least partially disposed within the plasma chamber; the plasma torch being configured to be connected to a power source; and a spectrometer having a line of sight into the plasma chamber; wherein the spectrometer is operable to detect an analyte of interest in the sample fluid when the sample fluid emitted by the plasma torch is vaporized by energizing the plasma torch to form a plasma; wherein the plasma torch apparatus includes: a first electrode having a needle and a second electrode having a tube; wherein the first electrode has a deflector connected to the needle at its base, and the deflector having a parabolic shape.

[0466] Example 210 - A sample analysis system comprising: a plasma torch apparatus including a plasma chamber and a plasma torch at least partially disposed within the plasma chamber; the plasma torch being configured to be connected to a power source; a spectrometer having a line of sight into the plasma chamber; and a fan connected to the plasma torch apparatus for providing a vacuum or positive pressure to the plasma chamber; wherein the spectrometer is operable to detect an analyte of interest in the sample fluid when the sample fluid emitted by the plasma torch is vaporized to form a plasma by energizing the plasma torch.

[0467] Example 211 - The sample analysis system according to Example 210 further includes a fluid retention section disposed within the plasma chamber and extending through the plasma torch device to allow fluid to be discharged from the plasma chamber.

[0468] Example 212 - A sample analysis system according to Example 211, wherein the fluid retention section has an inlet, and the inlet is located above the bottom of the plasma chamber.

[0469] Example 301 - A sample analysis system with a lens defogging device, the sample analysis system comprising: a plasma torch assembly including a body defining a plasma chamber and a plasma torch supported by the body within the plasma chamber; the plasma torch being electrically connected to a power source and operable to form a plasma from a sample fluid within the plasma chamber when energized; a spectrometer having a line of sight into the plasma chamber, the spectrometer being configured and operable to analyze the plasma to measure an analyte of interest in the sample fluid by means of light emitted by the plasma; the spectrometer including components connected to the plasma chamber. A light-collecting tube with visible communication to the chamber, the light-collecting tube including a near end and a far end, the far end being equipped with a lens configured to collect light emitted by the plasma; a gas hood including a hollow body including a near end, a far end, and a central passage extending between the near end and the far end, the light-collecting tube being at least partially inserted into the central passage such that the lens-equipped far end of the light-collecting tube is at least partially enclosed by the gas hood; the far end of the gas hood including a gas outlet port and a gas inlet port fluidly connected to a pressurized gas source; wherein the gas hood is configured and operable to discharge an airflow across the exposed surface of the lens to at least minimize fogging of the lens.

[0470] Example 302 - A sample analysis system according to Example 301, wherein the light-collecting tube extends cantilevered from the spectrometer into the plasma chamber.

[0471] Example 303 - A sample analysis system according to Example 302, wherein the light-collecting tube is supported only by the spectrometer.

[0472] Example 304 - A sample analysis system according to Example 302, wherein the light-collecting tube is fully inserted into the central passage and enclosed by the gas hood.

[0473] Example 305 - A sample analysis system according to Example 302, wherein the cross-sectional shape of the central passage of the gas hood is configured to be complementary to the cross-sectional shape of the light-collecting tube, such that the light-collecting tube can be slidably inserted into the central passage through the proximal end of the gas hood.

[0474] Example 306 - A sample analysis system according to Example 305, wherein the cross-sectional shape of the central passage of the gas hood and the cross-sectional shape of the light collecting tube are both circular.

[0475] Example 307 - A sample analysis system according to any one of Examples 301 to 306, wherein the gas inlet port and the gas outlet port extend laterally through the distal end of the gas hood into the central passage, and the gas inlet port and the gas outlet port are positioned opposite each other diametrically.

[0476] Example 308 - A sample analysis system according to Example 307, wherein the central pathway terminates at the distal end of the gas hood at an axial aperture, the axial aperture being axially aligned with the lens such that the line of sight of the spectrometer passes through the lens and the axial aperture into the plasma chamber.

[0477] Example 309 - A sample analysis system according to Example 308, wherein the distal portion of the central passage adjacent to the distal end of the gas hood includes a truncated cone section.

[0478] Example 310 - A sample analysis system according to Example 309, wherein the diameter of the axial hole is smaller than the diameter of the central passage at the proximal end of the gas hood.

[0479] Example 311 - A sample analysis system according to Example 309, wherein the diameter of the central passage adjacent to the truncated conical section is greater than the diameter of the axial hole.

[0480] Example 312 - A sample analysis system according to Example 311, wherein the diameter of the central passage decreases as it moves toward the axial hole.

[0481] Example 313 - A sample analysis system according to any one of Examples 309 to 312, wherein the gas inlet port and the gas outlet port are disposed within the truncated conical section.

[0482] Example 314 - A sample analysis system according to any one of Examples 301 to 313, wherein the cross-sectional flow area of ​​the gas inlet port is smaller than the cross-sectional flow area of ​​the gas outlet port.

[0483] Example 315 - A sample analysis system according to Example 314, wherein the gas inlet port is circular in shape and the gas outlet port includes an arc-shaped, elongated slot.

[0484] Example 316 - A sample analysis system according to Example 301, wherein the gas hood is detachably secured to the light collecting tube via threaded fasteners.

[0485] Example 317 - A sample analysis system according to Example 316, wherein one end of the threaded fastener engages with an annular recess formed on the outer surface of the light collector tube to axially lock the gas shroud to the light collector tube.

[0486] Example 318 - A sample analysis system according to Example 301, wherein the gas hood is configured to discharge the gas tangentially onto the exposed surface of the lens to form a gas curtain between the lens and the plasma torch.

[0487] Example 319 - A sample analysis system according to Example 302, wherein the gas inlet port is fluidly connected to a pressurized gas port via a gas flow conduit extending through a portion of the plasma chamber.

[0488] Example 320 - A sample analysis system according to Example 302, wherein the gas outlet port is configured to discharge the gas into the plasma chamber, and the discharge direction is not toward the plasma torch to avoid affecting the plasma.

[0489] Example 321 - A method for connecting a gas shroud to a light-collecting tube of a spectrometer, the method comprising: axially aligning the gas shroud and the light-collecting tube, each including a body, the body including a proximal end, a distal end, a passage extending between the proximal end and the distal end, and an axis extending between the proximal end and the distal end; inserting the distal end of the light-collecting tube through the proximal end of the gas shroud into the passage of the gas shroud; axially advancing the light-collecting tube through the central passage until a lens on the distal end of the light-collecting tube is positioned adjacent to a gas inlet port and a gas outlet port located proximal to the distal end of the gas shroud; and securing the gas shroud to the light-collecting tube.

[0490] Example 322 - The method according to Example 321, wherein the lens of the light-collecting tube is positioned adjacent to a truncated section of the passage of the gas shroud, the truncated section defining the gas inlet port and the gas outlet port.

[0491] Example 323 - The method according to Example 322, wherein when the lens is fixed to the light collecting tube, the lens is spaced apart from the distal end of the gas shroud.

[0492] Example 324 - The method according to Example 321, wherein the cross-sectional shape of the passage of the gas shroud is configured to be complementary to the cross-sectional shape of the light collecting tube, such that the light collecting tube can be slidably inserted into the passage of the gas shroud.

[0493] Example 325 - The method according to Example 324, wherein the cross-sectional shape of the central passage of the gas hood and the cross-sectional shape of the light collecting tube are both circular.

[0494] Example 326 - A method according to any one of Examples 321-325, wherein the gas inlet port and the gas outlet port extend laterally through the distal end of the gas hood into the passage of the gas hood, and the gas inlet port and the gas outlet port are positioned diametrically opposite each other.

[0495] Example 327 - The method according to Example 326, wherein the passage of the gas shroud terminates at an axial aperture, the axial aperture being axially aligned with the lens, such that the line of sight of the spectrometer passes through the lens and the axial aperture into the plasma chamber.

[0496] Example 328 - The method according to Example 327, wherein the diameter of the axial hole is smaller than the diameter of the passage at the proximal end of the gas shroud.

[0497] Example 329 - The method according to Example 328, wherein the diameter of the passage of the gas shroud adjacent to the axial hole decreases as it moves toward the distal end of the gas shroud.

[0498] Example 330 - The method according to any one of Examples 321-329, wherein the cross-sectional flow area of ​​the gas inlet port is smaller than the cross-sectional flow area of ​​the gas outlet port.

[0499] Example 331 - The method according to Example 330, wherein the gas inlet port is circular in shape and the gas outlet port includes an arc-shaped, elongated slot.

[0500] Example 332 - The method according to Example 321, wherein the gas hood is detachably secured to the light collecting tube via threaded fasteners.

[0501] Example 333 - The method according to Example 332, wherein one end of the threaded fastener engages with an annular recess formed on the outer surface of the light collecting tube to axially lock the gas shroud to the light collecting tube such that the gas shroud cannot be axially pulled out from the light collecting tube.

[0502] Example 334 - The method according to Example 321, wherein the gas hood is configured to discharge the gas tangentially onto the exposed surface of the lens.

[0503] Example 335 - The method according to Example 321, wherein the gas inlet port is fluidly connected to the pressurized gas port via a gas flow conduit extending through a portion of the plasma chamber.

[0504] Example 336 - A plasma torch apparatus for analyzing sample fluids, the apparatus comprising:

[0505] The system comprises: a main body defining a plasma chamber; a plasma torch disposed within the plasma chamber, the plasma torch including an anode and a cathode, either of which is configured to introduce the sample fluid into the plasma chamber; the plasma torch being electrically connected to a power source and operable to form a plasma from the sample fluid when the plasma torch is energized; and a spectrometer having a line of sight into the plasma chamber, the spectrometer being configured and operable to analyze the plasma to measure analytes of interest in the sample fluid by means of light emitted by the plasma. A plasma torch cleaning apparatus supported by the main body, the plasma torch cleaning apparatus comprising: a housing supported from the main body; an actuator supported by the housing; a pair of movable brushes, each brush including a plurality of flexible cleaning elements configured to engage and clean the anode and the cathode; the brushes being coupled to the actuator; wherein the actuator is configured and operable to move the brushes between an extended position and a retracted position, in the extended position, in which the plurality of cleaning elements are slidably engaged with the anode and the cathode; and in the retracted position, in which the plurality of cleaning elements are withdrawn from the anode and the cathode.

[0506] Example 337 - A plasma torch apparatus according to Example 336, wherein the actuator is a linear actuator configured to cause the brush to move linearly between the extended position and the retracted position.

[0507] Example 338 - A plasma torch apparatus according to Example 337, wherein the anode and the cathode are vertically aligned along the torch centerline axis, and the brush travels along an actuation axis defined by the actuator, the actuation axis being transverse to the torch centerline axis.

[0508] Example 339 - A plasma torch apparatus according to Example 337 or 38, wherein the actuator is coupled to the brush via a brush holder.

[0509] Example 340 - A plasma torch apparatus according to Example 339, wherein the brush holder is connected to a retractable operating rod of the actuator.

[0510] Example 341 - A plasma torch apparatus according to Example 340, wherein the brush holder includes a central through-hole that receives a threaded fastener that connects the brush holder to the operating rod.

[0511] Example 342 - A plasma torch apparatus according to Example 340, wherein each of the brushes includes a handle coupled to the brush holder.

[0512] Example 343 - A plasma torch apparatus according to Example 342, wherein the brush holder includes a pair of brush mounting holes, and the handle of each brush is inserted into one of the brush mounting holes.

[0513] Example 344 - A plasma torch apparatus according to Example 343, wherein the brush is secured to the brush holder via a positioning screw, the positioning screw being arranged and operable to engage the handle.

[0514] Example 345 - A plasma torch apparatus according to Example 344, wherein the positioning screw is received in a threaded retaining hole extending through the brush holder, the threaded retaining hole intersecting perpendicularly with the brush mounting hole.

[0515] Example 346 - A plasma torch apparatus according to Example 340, wherein the brush holder includes a laterally extending guide protrusion disposed on each of a pair of opposing sides of the brush holder.

[0516] Example 347 - According to the plasma torch apparatus of Example 346, each of the guide protrusions is slidably received between a pair of guide rods that project outward from the housing toward the plasma torch.

[0517] Example 348 - A plasma torch apparatus according to Example 347, wherein, as the brush moves between the extended position and the retracted position, the guide protrusion moves toward and away from the plasma torch together with the brush holder.

[0518] Example 349 - A plasma torch apparatus according to any one of Examples 339-347, wherein the brush holder has a block shape.

[0519] Example 350 - A plasma torch apparatus according to any one of Examples 339-348, wherein the housing is slidably mounted on a pair of support columns of the body, and the housing is vertically movable along the support columns in a plurality of vertical positions to align the pair of brushes with the anode and the cathode.

[0520] Example 351 - A plasma torch apparatus according to Example 350, wherein each of the support columns is slidably received in a mating mounting through-hole formed from the top to the bottom of the housing, the housing extending cantileveredly from the support column.

[0521] Example 352 - A plasma torch apparatus according to Example 351, wherein the housing is lockable in one of the plurality of vertical positions via a positioning screw inserted through the housing and engaging the support column.

[0522] Example 353 - A plasma torch apparatus according to Example 341, wherein the housing includes a rear wall, a side wall, and a pair of laterally spaced front short walls, the rear wall, the side wall, and the pair of front short walls together defining an axially elongated cavity in which the actuator is received, wherein when the brush is in the extended position, the operating rod of the actuator is capable of extending through an inlet opening of the axially elongated cavity defined between the front short walls.

[0523] Example 354 - A plasma torch apparatus according to Example 341, wherein the housing includes a cup-shaped brush enclosure including a mounting flange, the brush enclosure defining an open-forward cavity in which the brush is partially received.

[0524] Example 355 - A plasma torch apparatus according to Example 354, wherein the mounting flange is configured to be mounted to a side panel of the body of the plasma torch apparatus.

[0525] Example 356 - A plasma torch apparatus according to any one of Examples 336-355, wherein the brush is a tubular brush, and the cleaning element is in the form of bristles extending 360 degrees around the brush.

[0526] Example 357 - A plasma torch apparatus according to Example 356, wherein the bristles are metal bristles.

[0527] Example 358 - A plasma torch apparatus according to Example 357, wherein the bristles are made of stainless steel.

[0528] Example 359 - A method for cleaning a plasma torch apparatus capable of being operated to excite a sample fluid to generate plasma, the method comprising: mounting a housing of a cleaning device onto the plasma torch apparatus, the cleaning device including an actuator including a retractable operating lever coupled to a pair of brushes; moving the pair of brushes from a retracted position to an extended position via actuation of the actuator; slidably engaging cleaning elements of the brushes with the anode and cathode of the plasma torch; and returning the pair of brushes to the retracted position; wherein the cleaning elements are operable to remove deposits formed on the anode and cathode due to the excitation of the sample fluid to generate plasma.

[0529] Example 360 ​​- The method according to Example 359, wherein the actuator is a linear actuator that causes the pair of brushes to move linearly between the retracted position and the extended position.

[0530] Example 361 - The method according to Example 359 or 60, wherein the installation step includes the following steps: vertically adjusting the position of the housing relative to the plasma torch device such that the pair of brushes are horizontally aligned with the anode and the cathode.

[0531] Example 362 - According to the method of Example 361, the step of vertically adjusting the position of the housing includes: sliding the housing along a pair of support columns of the plasma torch apparatus, the housing being slidably mounted on the pair of support columns.

[0532] Example 363 - The method according to Example 362 further includes the step of locking the housing to each of the support posts with positioning screws while the pair of brushes are horizontally aligned with the anode and the cathode.

[0533] Example 364 - The method according to Example 362 or 63, wherein the housing is cantilevered and supported by the support column.

[0534] Example 365 - The method according to Example 360, wherein the operating lever of the actuator is coupled to a brush holder, which in turn is coupled to the pair of brushes.

[0535] Example 366 - The method according to Example 365, wherein the brush holder includes a pair of guide protrusions, and the step of moving the pair of brushes from the retracted position to the extended position via actuating the actuator includes: enabling each of the guide protrusions to slide between a corresponding pair of guide rails supported by the housing.

[0536] Example 367 - The method according to Example 366, wherein each of the guide protrusions extends outward from one of the sides of the brush holder.

[0537] Example 368 - A method according to any one of Examples 359-367, wherein the anode and the cathode are vertically aligned along the torch centerline axis, and the brush travels along an actuation axis defined by the actuator, the actuation axis being transverse to the torch centerline axis.

[0538] Example 369 - The method according to Example 359, wherein the sample fluid comprises agricultural sample material.

[0539] Example 370 - The method according to any one of Examples 359-369, wherein the cleaning element of the brush is made of metal.

[0540] While the foregoing description and figures illustrate some exemplary systems, it should be understood that various additions, modifications, and substitutions can be made thereto without departing from the spirit, scope, and definition of the equivalents of the appended claims. In particular, it will be apparent to those skilled in the art that the invention can be embodied in other forms, structures, arrangements, proportions, dimensions, and other elements, materials, and components without departing from the spirit or essential characteristics of the invention. Furthermore, various changes can be made to the methods / processes described herein. Those skilled in the art will further appreciate that the invention can be used with many modifications to structure, arrangement, proportions, dimensions, materials, components, and other aspects without departing from the principles of this disclosure, and these modifications can be used in practicing the invention, particularly suited to specific environments and operational requirements. Therefore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects, and the scope of the invention is defined by the appended claims and their equivalents, and is not limited to the foregoing description or embodiments. Rather, the appended claims should be interpreted broadly to include other variations and embodiments of the invention that can be practiced by those skilled in the art without departing from the scope and definition of the equivalents of the invention.

Claims

1. A sealing system for pressure balancing of a pump, the sealing system comprising: A pump body and an operating piston, the pump body defining a pump orifice, the operating piston being slidably disposed within the pump orifice for movement in opposite axial directions; The operating piston defines a sealing interface with the wall of the pump orifice; A first pressure zone is formed on the first side of the sealing interface; A second pressure zone is formed on the second side of the sealing interface; Pilot fluid is disposed on both the first side and the second side of the sealing interface; The second side of the sealing surface is fluidly connected to a pressure control device, which is operable to adjust the pressure of the pilot fluid in the second pressure zone.

2. The sealing system according to claim 1, wherein, The pressure control device is configured such that the second pressure of the pilot fluid generated in the second pressure zone is lower than the first pressure in the first pressure zone.

3. The sealing system according to claim 2, wherein, The first pressure is a negative pressure, and the second pressure is a negative pressure lower than the first pressure.

4. The sealing system according to any one of claims 1-3, wherein, The pressure control device is a vacuum pump.

5. The sealing system according to any one of claims 1-4, further comprising: A first sealing piston is disposed in the pump hole, and the first sealing piston is connected to the operating piston in a spaced-out relationship to form a first piston assembly; A first intermediate chamber for pressure balance is formed within the pump orifice, between the operating piston and the first sealing piston, and the first intermediate chamber defines the second pressure zone.

6. The sealing system according to claim 5, wherein, The first intermediate chamber is movable together with the first piston assembly within the pump orifice in opposite axial directions.

7. The sealing system according to claim 5 or 6, further comprising: A pressure relief port, the pressure relief port being defined within the pump body; A second piston assembly, slidably disposed within the pressure relief orifice for movement in opposite axial directions, the second piston assembly including a pressure relief piston spaced apart from and connected to a second sealing piston; A pressure-balanced second intermediate chamber is formed within the pressure relief hole and between the pressure relief piston and the second sealing piston, the second intermediate chamber defining a third pressure zone containing the pilot fluid; The first intermediate chamber of the first piston assembly is fluidly connected to the second intermediate chamber; The third pressure zone is in fluid communication with the second pressure zone.

8. The sealing system according to claim 7, wherein, The pressure in the third pressure zone is equal to the second pressure in the second pressure zone formed by the first intermediate chamber within the pump orifice.

9. The sealing system according to claim 7 or 8 further includes a pressure relief spring acting on the second piston assembly within the pressure relief hole.

10. The sealing system of claim 5 or 6, further comprising a linear actuator coupled to the first piston assembly, the linear actuator being configured to move the first piston assembly in opposite axial directions.

11. The sealing system according to any one of claims 1-10, further comprising an elastically deformable diaphragm disposed at a pumping chamber formed in the body of a pump and containing a process fluid, the process fluid being in contact with the working side of the diaphragm, and the pumping chamber being fluidly connected to a first pressure zone, the first pressure zone containing a pilot fluid located on the pilot side of the diaphragm.

12. The sealing system according to claim 11, wherein, The piston is moved in the pump orifice in a first axial direction, causing the diaphragm to pump the process fluid out of the pumping chamber, and the piston assembly is moved in the opposite second axial direction, causing the diaphragm to draw the process fluid into the pumping chamber on the working side of the diaphragm.

13. The sealing system according to any one of claims 1-12, wherein, The pilot fluid is oil.

14. The sealing system according to claim 10, wherein, The operating piston and the pump orifice define a positive displacement injection pump.

15. A sealing system for pressure balancing of a positive displacement pump, the sealing system comprising: A sealing interface is defined between a sealing member and a pump orifice, the sealing member being able to slide in opposite axial directions within the pump orifice; A first pressure zone is formed in the pump orifice on a first side of the sealing interface, the first pressure zone containing a first capture volume of pilot fluid, the pilot fluid being operable to act on a displaceable pumping element. A second pressure zone is formed in the pump orifice on the second side of the sealing interface, the second pressure zone containing a second capture volume of pilot fluid; The second pressure zone is fluidly connected to a pressure reducing device, which is operable to reduce the second pressure of the pilot fluid in the second pressure zone to a pressure lower than the first pressure of the pilot fluid in the first pressure zone.

16. The sealing system according to claim 15, wherein, The first pressure is a negative pressure, and the second pressure is a negative pressure lower than the first pressure.

17. The sealing system according to claim 15 or 16, wherein, The pressure-reducing device is a vacuum pump.

18. The sealing system according to any one of claims 15-17, wherein, The pump orifice is integrally formed in the pump body, and the sealing member is an operating piston that can be slidably disposed within the pump orifice.

19. The sealing system according to claim 18, wherein, The operating piston is connected to a linear actuator configured to move the operating piston in opposite linear directions.

20. The sealing system according to claim 18 or 19, wherein, The operating piston is fixedly connected to the sealing piston in the pump orifice to form a pump assembly, wherein an intermediate chamber is formed in the pump orifice between the operating piston and the sealing piston, and the intermediate chamber defines the second pressure zone.

21. An air removal system for a fluid, the air removal system comprising: An air removal device that is fluidly connected to a reservoir containing liquid; The air removal device includes an air-permeable membrane, forming a transportable gas interface between a first side of the air-permeable membrane in contact with a liquid fluid and a second side exposed to a vacuum applied by a vacuum source; The permeable membrane is configured to allow air entrained in the liquid to be drawn through the membrane to the second side, while retaining the liquid on the first side.

22. The air removal system according to claim 21, wherein, The air removal device includes a housing that can be mechanically coupled to a fluid component body, the fluid component body defining a reservoir containing the liquid.

23. The air removal system according to claim 22, wherein, The housing includes a receiver provided with the air-permeable membrane, the receiver being fluidly connected to the reservoir via an air inlet located on the first side of the air-permeable membrane, and the receiver being fluidly connected to a vacuum source located on the second side of the air-permeable membrane.

24. The air removal system according to claim 23, wherein, The receiver includes: a first wall located on the first side of the air-permeable membrane, the first wall including a plurality of first airflow through openings in fluid communication with the liquid; and a second wall facing the first wall, the second wall including a plurality of second airflow through openings located on the second side of the air-permeable membrane and in fluid communication with the vacuum source.

25. The air removal system according to any one of claims 22-24, wherein, The fluid component body defining the reservoir is part of a pump.

26. The air removal system according to claim 25, wherein, The pump includes an elastically deformable diaphragm operable to pump a process fluid on a working side of the diaphragm, the fluid being a pilot fluid that acts on a pilot side of the diaphragm to actuate the diaphragm.

27. The air removal system according to claim 26, wherein, The piston acts on the pilot fluid. The piston is slidably disposed within a pump orifice and coupled to a linear actuator that is operable to move the piston, thereby displacing the pilot fluid and actuating the diaphragm.

28. The air removal system according to claim 23, wherein, The air inlet is partially defined by a rod that can be at least partially inserted into an opening in a flow channel in the body of the fluid component.

29. The air removal system according to any one of claims 22-28, wherein, The housing includes a first half-section detachably coupled to a mating second half-section, and the receiver is defined by the first half-section and the second half-section together.

30. The air removal system according to claim 29, wherein, The shell is cylindrical.

31. The air removal system according to any one of claims 21-30, wherein, The air-permeable membrane is formed of silicone rubber.

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