Fluid refractive index optimized particle counter

Abstract

To provide an optical particle counter system capable of analyzing particles in consideration of a refractive index of a carrier fluid to be analyzed.SOLUTION: An optical particle counter 100 includes a light source 220 for generating an electromagnetic radiation beam, a floating chamber 210 that flows a fluid containing particles along a flowing direction through the electromagnetic radiation beam, a light collection system 230 that collects electromagnetic radiation scattered or emitted from the particles to direct the radiation toward a detector 240, and a refraction index optimizer 101 connected to one or more of the light source, the light collection system and the detector so as to be operative to include optical communications.SELECTED DRAWING: Figure 1

Description

Cross - Reference to Related Applications

[0001]

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 62 / 725,777, filed on August 31, 2018, the entire disclosure of which is incorporated herein by reference in its entirety and for all purposes not inconsistent herewith.

[0002] Background of the Invention

[0003]

[0002] Particle counters play an important role in modern manufacturing technologies to monitor the environment of micro - and nano - scale particles that pose problems in various industries, including semiconductor manufacturing and pharmaceutical or biotech production. As manufacturing processes advance, there is an increasing need to detect, characterize, or remove ever - smaller particles.

[0004]

[0003] One common type of particle counter is the optical particle counter. These counters monitor a fluid flow and characterize the particles within it by projecting electromagnetic radiation (typically via a laser) into a flow cell. The electromagnetic radiation interacts (scatters, reflects, obscures, emits, etc.) with the particles found within the flow cell. The electromagnetic radiation is then analyzed to determine the number or characteristics of the particles present in the flow cell.

[0005]

[0004] As particle size decreases, the complexity of the optical components for detecting particles increases dramatically. For detecting particles smaller than 50 nm (which increases as particle size decreases), very powerful lasers and detectors must be precisely aligned to accurately detect and characterize the particles, and often require extensive calibration to be effective and accurate. However, in many industries, various different fluids are used in cleanrooms or controlled environments, and changes in refractive index can reduce or eliminate the effectiveness of particle detectors, as changes in refractive index alter the path of electromagnetic radiation as it passes through the fluid cell. Changes in path alter the ideal measurement point (focal point) for the collection and / or detection system analyzing the electromagnetic radiation, which may prevent accurate characterization of particles passing through the fluid cell. In some cases, particle counters may be manually recalibrated, but calibration would be required each time a fluid with a different refractive index is analyzed with the particle counter. Calibration is time-consuming, expensive, and requires the particle counter to be taken offline.

[0006]

[0005] As can be seen from the above, there remains a need in the art for an optical particle counting system that can be used with different liquid carrier fluids without the need for recalibration, which is achieved by taking into account the refractive index of the carrier fluid. Furthermore, there is a need for an advanced optical particle counting system that can detect nanoscale particles (e.g., less than 100 nm, more preferably less than 50 nm, and possibly less than 20 nm) and is compatible with multiple carrier fluid compositions.

[0007] Brief summary of the invention

[0008]

[0006] This document provides optical particle analyzers or counters that take into account and adjust for the refractive index of the carrier fluid being analyzed, and related methods of use. The analyzers are robust and can be implemented in a variety of optical particle counters, including obscured light, reflected light, synchrotron and scattered light particle counters. The analyzers are useful for any fluid, including gases or liquids. In some cases, the analyzer can account for the difference in refractive index between two liquids, for example, ultrapure water and an acid (e.g., sulfuric acid, hydrochloric acid, hydrofluoric acid, acetic acid, phosphoric acid, chromium phosphoric acid, etc.). The analyzer can be configured to take into account the difference in refractive index between different fluids, including liquids and gases. By taking into account the refractive index of the carrier fluid, the described analyzers and methods can also detect and characterize smaller particles (e.g., nanoscale) more accurately and reliably with greater sensitivity.

[0009]

[0007] By taking refractive index into consideration, the described systems and methods can also be optimized for channel setting for particle characterization. Since the refractive index is known (for example, by knowing the fluid composition and / or by measuring the refractive index with an instrument such as a refractometer), not only is particle detection improved, but the size or size range determined by the particle counter becomes more accurate.

[0010]

[0008] In one embodiment, the optical particle analyzer comprises: (i) a light source (e.g., a laser or LED) for generating a beam of electromagnetic radiation; ii) a flow chamber for generating scattered or emitted electromagnetic radiation by flowing a fluid containing particles along the flow direction through the beam of electromagnetic radiation; (iii) an optical collection system for collecting the scattered or emitted electromagnetic radiation from an observation area (if present) containing particles and directing it onto a detector; and iv) a refractive index optimizer operably connected to one or more of the laser, the optical collection system, or the detector, including optical communication, to optimize the collection of electromagnetic radiation by the detector. Thus, the refractive index optimizer is configured, in combination with and controlled by the other optical components, to control the focus of the beam of electromagnetic radiation in the fluid through which particles are flowing, based on the refractive index of the fluid, and to optimize the collection of electromagnetic radiation by the detector. Not only can the beam of electromagnetic radiation be appropriately focused onto a desired observation area, including corresponding to a desired portion of the flow cell, but the radiation collected after interaction with the fluid sample can also be appropriately focused onto the detector, thereby increasing the sensitivity, resolution, and / or accuracy of the particle analyzer.

[0011]

[0009] The analyzers and methods described herein can rapidly and automatically describe changes in refractive index in numerous ways. For example, an analyzer may have a positioner or motor, or other means, to shift the position or angle of any of the components, such as a light source including an electromagnetic radiation collection system or an optical component. The analyzer may also adjust the light source (e.g., a laser) by changing the beam shape, beam position, or beam intensity. Each of these describes changes in refractive index by optimizing the focus of the beam and collection / detection system, regardless of the fluid refractive index. The positioner or motor may be configured to provide positioning in the range of millimeters to microns, e.g., 10 mm to 0.1 μm. The amount of motion required will vary depending on the expected range of refractive indices. For small differences where the difference in refractive index is negligible, small motions are required to achieve the desired optimization. Larger differences require relatively large movements. Thus, various positioners or motors such as picomotor parallel movement stages, rack and pinion worm gears, and / or linear actuators can be utilized. Similarly, the adjustment angle for mirrors, lenses, or light sources can range from 10° to 0.01°, and a rotating picomotor stage can be used that can account for very small but significant refractive index differences between fluids.

[0012]

[0010] The refractive index optimizer may be, in an optical sense, a beam shaping optical assembly positioned between the optical laser and the fluid chamber, and the refractive index optimizer adjusts the beam shape or beam position of the electromagnetic radiation in the fluid chamber to optimize the collection of the electromagnetic radiation.

[0013]

[0011] The refractive index optimizer is operably connected to the laser and can adjust the position of the laser relative to the fluid chamber to optimize the collection of electromagnetic radiation. The adjustment can be performed by any means known in the art, for example, using a positioner such as an electric motor, piezoelectric actuator, moving stage, micrometer, picometer, etc., to reliably position optical components such as a light source including the laser. Next, the laser orientation adjustment adjusts the direction of the electromagnetic radiation beam, thereby ensuring that the beam's focal point intersects the observation window, taking into account the refractive index of the fluid (e.g., a liquid or gaseous composition).

[0014]

[0012] The analyzers and methods described herein are also compatible with positioners or controllers that position or control optical components located optically downstream of a light source. For example, instead of controlling the position of the light source, optical mirrors, lenses, etc., can be controlled via motors, positioners and / or actuators to change the beam of electromagnetic radiation (including its position).

[0015]

[0013] The refractive index optimizer is operably connected to the acquisition system and can adjust the depth of focus of the acquisition system relative to the fluid chamber to optimize the acquisition of electromagnetic radiation. This operable connection refers to lens position control and / or control of lens curvature or type (including lens replacement or control of curvature-controllable lenses).

[0016]

[0014] The refractive index optimizer is operably connected to the detector and can adjust the position of the detector relative to the fluid chamber to optimize the collection of electromagnetic radiation, such as by using one or more of a motor, a positioner, or an actuator.

[0017]

[0015] The refractive index optimizer can adjust the position of the laser, collection system, or detector in the x, y, z axes or any combination thereof. The refractive index optimizer can maximize the output signal from the detector.

[0018]

[0016] Various methods can be used to provide the analyzers described herein with the actual or estimated refractive index of the fluid being analyzed. The refractive index may be input by the user into the optical particle counter or refractive index optimizer, for example, if the refractive index is provided as a number, or if the fluid composition and / or concentration is provided and the refractive index is determined from a lookup table.

[0019]

[0017] The analyzer and method may further include a fluid chamber, more specifically a refractometer operably connected to the fluid introduced into the fluid chamber, and a refractive index optimizer, the refractometer providing a refractive index to the refractive index optimizer. The described analyzer and method may further include an optical particle counter and a processor operably connected to the refractive index optimizer, the optical particle counter functioning as a refractometer. The refractive index optimizer can optimize the collection of electromagnetic radiation at refractive indices selected from 1.3 to 1.6. The refractive index optimizer can provide contrast-detection autofocus (CDAF) or phase-detection autofocus (PDAF).

[0020]

[0018] Any apparatus or method provided herein preferably includes a processor to facilitate automation of the apparatus or method. For example, based on a known or measured refractive index input to the processor, the processor may determine focus, which includes sending control signals to a refractive index optimizer to control one or more incident light, such as the position and orientation of a light source, beam shape, optical collection system configuration, and / or detector position, thereby avoiding intervention by an active user. "Optical collection system configuration" may be represented by optical parameters including the position / orientation of the optical components of the optical collection system and / or the type of optical components, such as lens type or lens shape.

[0021]

[0019] In one embodiment, an optical particle analyzer including a counter comprises: i) a laser for generating a beam of electromagnetic radiation; ii) a fluid chamber for generating scattered or emitted electromagnetic radiation by flowing a fluid containing particles along the flow direction through the beam of electromagnetic radiation; iii) an optical collection system for collecting the scattered or emitted electromagnetic radiation from an observation area and directing it to a detector; and iv) a beam shaping optical assembly operably connected to the laser for adjusting the beam shape or beam position of the electromagnetic radiation, wherein the beam shaping optical assembly adjusts the beam shape or beam position based on the refractive index of the fluid.

[0022]

[0020] The optical particle analyzer further comprises a refractometer operably connected to a fluid chamber for determining the refractive index of a fluid, and a processor operably connected to the refractometer and a beam shaping optical assembly that adjusts the beam shape or beam position based on the refractive index determined by the refractometer.

[0023]

[0021] In one embodiment, a method for maximizing the signal output of an optical particle counter includes: i) preparing an optical particle counter comprising: a) a laser for generating an electromagnetic radiation beam; b) a fluid chamber for generating scattered or emitted electromagnetic radiation by flowing a particle-containing fluid along the flow direction through the beam of electromagnetic radiation; c) an optical collection system for collecting the scattered or emitted electromagnetic radiation from an observation area and directing it to a detector; and d) a beam-shaping optical assembly operably connected to the laser; ii) measuring the refractive index of the fluid in the fluid chamber; and iii) adjusting at least one of the following: the beam-shaping optical assembly for the beam shape and / or beam position of the electromagnetic radiation entering the fluid chamber, based on the measured refractive index; or the position of the laser, optical collection system, detector, or any combination thereof, based on the measured refractive index, to optimize the depth of focus of the electromagnetic radiation entering the fluid chamber and directed to the detector, thereby increasing the amount of electromagnetic radiation reaching the detector and maximizing the signal output of the optical particle counter.

[0024]

[0022] The refractive index can be automatically measured by a refractometer operably connected to the fluid. This embodiment is preferred when the user does not need to determine the fluid composition, or when the fluid composition may change over time, including in instruments that encounter batch-to-batch variations or normally different fluid compositions. In other words, the refractive index may be a time-varying refractive index, and the fluid composition may change over time sufficiently, depending on the application, so that the refractive index changes over time.

[0025]

[0023] However, this method is compatible with manually determined refractive indices by introducing a fluid with a known refractive index into a fluid chamber. For example, if the user is provided with a fluid composition, the refractive index of that fluid is looked up instead of measured, along with the corresponding input to the particle analyzer of the refractive index optimizer. Thus, this method may further include the step of determining the refractive index value by a lookup table and manually inputting the refractive index value to the particle analyzer.

[0026]

[0024] This method may further include the step of adjusting a beam shaping optical assembly to provide an optimized beam shape and / or beam position of electromagnetic radiation entering a flow chamber based on the refractive index.

[0027]

[0025] This method may further include the step of adjusting the position of the laser, the light collection system, the detector, or any combination thereof.

[0028]

[0026] In one embodiment, a method for maximizing the signal output of an optical particle counter includes: i) preparing an optical particle counter comprising: a) a laser for generating a beam of electromagnetic radiation; b) a fluid chamber for generating scattered or emitted electromagnetic radiation by flowing a particle-containing fluid along the flow direction through the beam of electromagnetic radiation; and c) an optical collection system for collecting the scattered or emitted electromagnetic radiation from an observation area and directing it to a detector; ii) measuring the refractive index of the fluid in the fluid chamber; and iii) adjusting the positions of the laser, the optical collection system, the detector, or any combination thereof to optimize the depth of focus of the electromagnetic radiation entering the fluid chamber, thereby increasing the amount of electromagnetic radiation reaching the detector and maximizing the signal output of the optical particle counter.

[0029] While not wishing to be bound by any particular theory, the fundamental principles believed or understood in relation to the apparatus and methods disclosed in this book can be described herein. Regardless of the ultimate accuracy of any mechanistic explanations or hypotheses, embodiments of the present invention are recognized as still being effective and useful.

Brief Description of the Drawings

[0030] [Figure 1] FIG. 1 illustrates an integrated refractive index optimizer and an optical particle counter. [Figure 2] FIG. 2 is a top view of a particle counter having a flow direction orthogonal to the plane to be observed. [Figure 3] FIG. 3 compares particles detected by optical particles in sulfuric acid. The left column represents the number of particles detected using a particle counter specially calibrated to detect at a high refractive index (~1.6), and the right represents analyzing the same fluid using a particle counter calibrated to detect particles in a low refractive index fluid such as water (~1.3). The difference in size reflects that the counting is significantly and meaningfully affected if the refractive index of the carrier fluid is not taken into account. Detailed Description of the Invention

[0031]

[0031] Generally, the terms and phrases used in this book have their technically recognized meanings and can be found by referring to standard texts, journal references, and the context known to those skilled in the art. The following definitions are provided to clarify their specific use in the context of the present invention.

[0032]

[0032] The term "refractive index optimizer" refers to a system or subsystem provided in an optical particle counter that allows the focus of the particle counter's optical system to be shifted based on the refractive index of the carrier fluid being analyzed by the particle counter. The refractive index optimizer can adjust the position or angle of one or more optical systems (e.g., light source, collection system, detector, beam shaping system, etc.) relative to the flow cell using motors, electronic devices, other moving systems, or a series of these moving systems. The refractive index optimizer may also adjust the beam shaping system, and the light source may change the beam shape, beam intensity, or beam target within the flow cell. The refractive index optimizer may include a control unit, one or more motors, a display, inputs (e.g., a keyboard or touchscreen, or a data link to another device such as a computer or smartphone), a processor, and / or a refractometer.

[0033]

[0033] "Flow direction" refers to the axis parallel to the direction in which the majority of the fluid moves when it is flowing. In the case of a fluid flowing through a straight flow cell, the flow direction is parallel to the path through which the majority of the fluid travels. In the case of a fluid flowing through a curved flow cell, the flow direction can be considered to be tangential to the path through which the majority of the fluid travels.

[0034]

[0034] "Optical communication" refers to components arranged so that light or electromagnetic radiation is transmitted between them.

[0035]

[0035] In this document, “optical component” is used broadly to refer to a component useful for generating, controlling / directing, and detecting electromagnetic radiation, specifically electromagnetic radiation introduced into a fluid sample and interacting with the fluid, including any particles suspended in the fluid. Examples include mirrors, lenses, and filters.

[0036]

[0036] In this document, “operably connected” is used broadly to refer to a configuration of elements such that the action or reaction of one element affects another element, but the functionality of each element is maintained. For example, this term can include elements that communicate optically with each other and do not necessarily have physical contact. For example, a refractive index optimizer operably connected to a light source such as a laser can include elements such as mirrors, lenses, filters, or other optical components that affect one or more characteristics of the light beam output but do not directly control the laser itself. Similarly, a refractive index optimizer operably connected to a detector can include control of the output beam to ensure that the output beam is properly guided to the detector. Of course, operably connected also includes embodiments in which there are more direct physical interconnections, such as a refractive index optimizer that includes a positioner resulting in the physical movement of the laser, detector, and / or components of the optical collection system.

[0037]

[0037] The term "positioner" is broadly used to refer to any known means in the art that reliably and reproducibly moves components, including those at the micron level. Examples, but not limited to, include electric motors, piezoelectric actuators, spring-loaded drives, micrometer-driven positioning stages, and micrometers. The systems and methods provided herein are compatible with manually or automatically controlled positioners. As long as the refractive index is known, optical components can be positioned at desired locations using a user or processor.

[0038]

[0038] "Light source" refers to a device or device component capable of delivering electromagnetic radiation to a sample. This term is used in a broad sense and is not limited to visible light from a visible light beam, etc., but includes any electromagnetic radiation. A light source can be embodied as a laser or laser array, such as a diode laser, diode laser array, diode laser-pumped solid-state laser, LED, LED array, vapor phase laser, solid-state laser, or a combination thereof. Unless otherwise specified, the term "optical laser" is interchangeable.

[0039]

[0039] The terms “electromagnetic radiation” and “light” are used synonymously in this document and refer to waves of electric and magnetic fields. Electromagnetic radiation useful in the methods of the present invention includes, but is not limited to, ultraviolet light, visible light, infrared light, or any combination having wavelengths from about 100 nanometers (nm) to about 15 microns (μm).

[0040]

[0040] The expression “detecting particles” broadly refers to sensing, identifying the presence of particles, and / or characterizing particles. In some embodiments, detecting particles refers to counting particles. In some embodiments, detecting particles refers to characterizing, and / or measuring the physical properties of particles, such as particle size, cross-sectional dimensions, shape, size, aerodynamic size, or any combination thereof.

[0041]

[0041] "Particles" refers to small objects that are often considered contaminants. Particles may also be any substance produced by the action of friction when two surfaces are in mechanical contact and there is mechanical movement. Particles may consist of aggregates of substances such as dust, dirt, smoke, ash, water, soot, metals, minerals, or any combination thereof or other substances or contaminants. "Particles" may also refer to biological particles, such as viruses, spores, and microorganisms including bacteria, fungi, archaea, protists, and other single-celled microorganisms, and in particular microorganisms having a size on the order of 1–15 μm. Particles may also refer to any small object that absorbs or scatters light and is therefore detectable by a light particle counter. As used in this text, "particles" is intended to exclude individual atoms or molecules of a carrier fluid, such as water molecules, process chemical molecules, oxygen molecules, helium atoms, nitrogen molecules, etc. The system and method can detect, determine the size of, and / or count particles containing aggregates of material having sizes of 10 nm, 20 nm, 30 nm, 50 nm, 100 nm, 500 nm, 1 μm or larger, or 10 μm or larger. Specific examples of particles include those between 20 nm and 50 nm, between 50 nm and 50 μm, between 100 nm and 10 μm, and between 500 nm and 5 μm.

[0042]

[0042] The terms “optical liquid particle counter” and “particle counter” are used interchangeably in this document and refer to a system capable of detecting particles suspended in a liquid, a system capable of determining the size of particles suspended in a liquid, a system capable of counting particles suspended in a liquid, a system capable of classifying particles suspended in a liquid, or any combination thereof. A typical optical liquid particle counter consists of several components, e.g., a source for generating a beam of electromagnetic radiation, an optical system for directing the beam to a region through which a fluid sample flows, e.g., a liquid or gas flowing through a flow cell. A typical optical liquid particle counter also includes a photodetector, such as a two-dimensional photodetector, a focusing optical system for detecting electromagnetic radiation obscured, scattered, or emitted by particles passing through the beam, and other electronics for processing and analyzing the electrical signals generated by the photodetector, including a current-to-voltage converter and signal filtering and amplification electronics. The optical particle counter may also include a pump for generating a flow to introduce the liquid sample into the detection region where the electromagnetic beam is present.

[0043]

[0043] "Fluid communication" refers to the arrangement of two or more objects, where the fluid is transported to one object, transported through one object, or transported from one object to another. For example, in some embodiments, if the fluid channel is directly provided between two objects, the two objects are in fluid communication with each other. In some embodiments, if the fluid channel is provided indirectly between two objects, for example by including one or more other objects or channels between the two objects, the two objects are in fluid communication with each other. In one embodiment, two objects present in a fluid body are not necessarily in fluid communication with each other unless the fluid from the first object is attracted to the second object, for example along a channel, passes through the second object, and / or does not pass through the second object.

[0044]

[0044] The following embodiments further illustrate the present invention, but of course should not be construed as limiting the scope of the present invention. [Example 1]

[0045]

[0045] This embodiment describes an optical particle counter that includes a refractive index optimizer that adjusts various aspects of the system (e.g., component positioning, beam characteristics) to ensure that the system's focus is positioned within an acceptable range and that the data generated is accurate. In these systems, the refractive index optimizer is an active design element that ensures that electromagnetic radiation is collected and then collected or amplified onto the detector from an ideal measurement point within the sample or fluid cell.

[0046]

[0046] Fluctuations in the fluid refractive index can cause a shift in the optical system focus within the measurement cell, which can affect the shape and position of the beam, as well as the region within the cell where the light is collected and properly gathered onto the detector. These fluctuations, individually or in combination, affect the performance of the particle counter in several ways.

[0047]

[0047] An integrated refractive index optimizer and optical particle counter are provided in Figure 1. As shown by the dotted line, the refractive index optimizer 101 is operably connected to one or more of the following: a light source 220, an optical collection system 230, a detection system 240, a refractometer 102, and / or a beam shaping optical assembly 203. The liquid particle counter 100 is provided in fluid communication with a liquid conduit 150 so that a liquid having particles 31 flows through the fluid chamber 210 of the particle counter. The light source 220, such as a laser or light-emitting diode, generates a beam of electromagnetic radiation 221 that passes through the fluid chamber 210, and this beam interacts with these particles as they pass through the fluid chamber in an observation area 211 that includes a focal point for a particular fluid in the fluid chamber 210. The transmitted, scattered, or emitted electromagnetic radiation is collected by the collection system 230 and directed to a detector system 240 that generates an electrical signal corresponding to the particles or characteristics of the particles passing through the fluid cell.

[0048]

[0048] A refractive index optimizer may also be used to control the depth of focus 231 such that the transmitted light from the collecting system 230 is focused, ideally, onto a plane corresponding to the detector elements of the detector system 240, thereby further optimizing the collection of electromagnetic radiation scattered or emitted by the particles 31 in the fluid 30. Control of the depth of focus is performed by any of the various means in the art, including adjusting the position of one or more optical components in one or more of the x, y, and z directions, as well as by the collecting lens and the curvature of such lens. Similarly, the actual detector 240 may be moved so that the position of the detector's detection plane corresponds to the depth of focus 231.

[0049]

[0049] Figure 1 is a schematic diagram illustrating the shielding or exclusion of a liquid particle counter. However, the concepts and embodiments described herein are also applicable to other types of particle counters, including scattered light or synchrotron radiation particle counters. Figure 2 shows, for example, the configuration of a scattered liquid particle counter, where the detection system is offset (e.g., by only 90 degrees) from the path of electromagnetic radiation 221 from the light source 220. Figure 2 provides a top view of the liquid particle counter, where the flow direction is perpendicular to the plane being observed. From this viewpoint, a fluid monitoring system located either upstream or downstream of the flow chamber 210 is not shown in Figure 2.

[0050]

[0050] As shown in Figure 1, the refractive index optimizer 101 can adjust changes in refractive index in many different ways. For example, one or more of the light source 220, the light collection system 230, and / or the detector 240 may include motors or other repositioning means relative to the other components, so that the system's focus can be adjusted by the refractive index optimizer 101 when a change in refractive index is input or detected. The analyzer can adjust the position or orientation of various components, either offline or online, of one or more components of the optical assembly, including shifting and / or rotating one or more components of the optical assembly around the X, Y, or Z axes, relative to the ideal focal point (measurement) point of the fluid cell 210. The refractive index optimizer 101 may be operably connected to the light source 220 or an optical component (e.g., a beam shaping optical system) 203, and the refractive index optimizer 101 may adjust beam shape, beam intensity, or beam position. The particle counter may have separate pre-calibrated positions for various common fluids or refractive indices.

[0051]

[0051] The refractive index optimizer 101 can be updated in several ways with changes in the refractive index of the carrier fluid. For example, the refractive index optimizer includes a processor 103 that can calculate or estimate the refractive index of the fluid using data received from the detector 240 or other components. The refractive index optimizer 101 may have an input and / or display, or be operably connected to an input and / or display of the particle counting system 100, and the user or input inputs the refractive index of the fluid, or the chemical composition and / or concentration of the fluid, and the refractive index optimizer 101 then determines the refractive index using a lookup table or algorithm. A refractometer 102 (or similar device) may be in fluid communication with the carrier fluid (ether via the conduit 150 or fluid chamber 210) and provided to communicate data with the refractive index optimizer 101. The refractometer 102 can provide the refractive index optimizer 101 with the calculated or estimated refractive index, for example, in real time. Furthermore, the refractometer 102 provides a signal to the refractive index optimizer 101 via data communication, which then interprets or calculates the refractive index of the fluid.

[0052]

[0052] In addition, the systems and methods described may utilize an autofocus method to adjust for changes in the refractive index of the carrier fluid. Generally, lasers are used to generate a beam of electromagnetic radiation. Particles along a fluid channel flow through the electromagnetic radiation, as do molecules in the fluid itself. When a scattered light collection and focusing optical system is aligned with a fluid of known refractive index, the mean square spot size, and therefore the image of scattered light from either particles or molecules, is focused onto the detector. Molecular scattering of the fluid caused by the impacting laser itself produces an image of the electromagnetic radiation of the laser within the fluid, which is imaged by the system detector. This laser image can be analyzed by an autofocus method. When multidimensional array detection is applied, autofocus can be achieved, for example, by contrast-detection autofocus (CDAF) or phase-detection autofocus (PDAF) methods. In single or individual detections, changes in the sample fluid change the refractive index, causing a focus shift in the image on the detector and a loss of collected incident power. These autofocusing methods and power losses can be output as real-time information to a refractive index optimizer to reshape both the laser beam and scattered light collection through optical lens assembly motion to refocus and maximize the power of both the electromagnetic radiation and particle scattered radiation of the laser.

[0053]

[0053] Figure 3 compares the particles detected by optical particles in sulfuric acid. The left side of the graph shows the number of particles detected using a particle counter specially calibrated to detect high refractive indices (~1.6), while the right side shows the analysis of the same fluid using a particle counter calibrated to detect particles in fluids with low refractive indices (~1.3), such as water. Figure 3 shows that in this embodiment, using an uncalibrated particle counter to account for refractive indices reduces detection capability for higher refractive indices.

[0054] Statements relating to reference and modification

[0055]

[0054] All references cited herein, including publications, patent applications, and patents, are incorporated herein by reference as if they were contained herein, with each reference individually and specifically indicated as being incorporated by reference.

[0056]

[0055] In the context of describing the invention (in particular in the context of the following claims), the use of the terms “a,” “an,” “the,” and “at least one” and similar referents should be interpreted as covering both singular and plural, unless otherwise indicated herein or unless the context clearly contradicts it. The use of the term “at least one” followed by a list of one or more items (e.g., “at least one of A and B”) should be interpreted as meaning one item selected from the listed items (A or B), or any combination of two or more listed items (A and B), unless otherwise indicated herein or unless the context clearly contradicts it. The terms “equip,” “have,” “include,” and “incorporate” should be interpreted as open-ended terms (i.e., “include but not limited to”), unless otherwise specified herein. The enumeration of value ranges in this document is intended merely as a concise way to refer individually to each independent value within the range, unless otherwise indicated herein, and each independent value is incorporated herein as if it were individually enumerated herein. All methods described herein may be performed in any suitable order unless otherwise indicated herein or unless it is clearly inconsistent with the context. The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended merely to better illustrate the invention and does not limit the scope of the invention unless specifically claimed. No language in any specification should be construed as indicating an element not claimed as essential to the practice of the invention.

[0057]

[0056] Preferred embodiments of the Invention are described herein, including the best mode known to the inventors for carrying out the Invention. Variations of these preferred embodiments will become apparent to those skilled in the art by reading the preceding description. The inventors expect that those skilled in the art will appropriately adopt such variations, and the inventors intend to carry out the Invention in ways other than those specifically described herein. Accordingly, the Invention includes all modifications and equivalents of the subject matter described in the claims appended herein, as permitted by applicable law. Furthermore, unless otherwise stated herein or unless it is clearly inconsistent with the context, any combination of all possible variations of the above elements is brought about by the Invention.

[0058]

[0057] All references throughout this Application, such as patent documents, patent application publications, and non-patent documents or other source materials, including issued or granted patents or equivalents, are incorporated into this Publication by reference as if they were incorporated individually by reference, provided that each reference does not contradict the disclosures of this Application in any way (for example, partially contradictory references are incorporated by reference except for the partially contradictory portion of the reference).

[0059]

[0058] The terms and expressions used herein are for illustrative purposes only and not for limiting purposes, and in the use of such terms and expressions there is no intention to exclude equivalents of the exhibited and described features or parts thereof, but it is recognized that various modifications are possible within the scope of the claimed invention. Accordingly, although the present invention is specifically disclosed by preferred embodiments, exemplary embodiments and optional features, it should be understood that modifications and variations of the concepts disclosed herein are accessible to those skilled in the art, and such modifications and variations are considered to be within the scope of the present invention as defined by the appended claims. The specific embodiments provided herein are examples of useful embodiments of the present invention, and it will be apparent to those skilled in the art that the present invention can be carried out using a number of variations of the devices, device components and method steps described herein. As will be apparent to those skilled in the art, the methods and devices useful for the method may include a number of optional compositions and processing elements and steps.

[0060]

[0059] If a group of substitutions is disclosed herein, it will be understood that all individual members and all subgroups of that group are disclosed separately. If a group of Markush or any other group is used herein, all individual members of the group, and all possible combinations and subcombinations of the group are intended to be included individually in this disclosure.

[0061]

[0060] Unless otherwise specified, the present invention can be carried out using any organization or combination of the components described or illustrated herein.

[0062]

[0061] Whenever a range, for example a temperature range, refractive index range, or composition or concentration range is described in the specification, it is intended that all intermediate and subranges, as well as all individual values ​​included within the described range, be included in the disclosure. It will be understood that any subrange or individual value within the range or subrange described herein may be excluded from the claims herein.

[0063]

[0062] All patents and publications described herein represent the level of the art to those skilled in the art relating to the present invention. References cited herein are incorporated herein by reference in their entirety to represent the state of the art as of the publication or filing date, and this information is intended to be used herein to exclude certain embodiments in the prior art where necessary. For example, if a composition is claimed, it should be understood that compounds that were publicly known and available in the art prior to the applicant's invention, including compounds for which a practicable disclosure is provided in the references cited herein, are not intended to be included in the composition claims herein.

[0064]

[0063] As used herein, “equipment” is synonymous with “include,” “contains,” or “characterized by,” and is comprehensive or open-ended and does not exclude additional, unlisted elements or method steps. As used herein, “consist of” excludes any elements, processes, or components not specified in the claim elements. As used herein, “essentially consists of” does not exclude materials or processes that do not substantially affect the basic and novel characteristics of the claim. In each embodiment herein, any of the terms “equipment,” “essentially consists of,” and “consist of” may be replaced with any of the other two terms. The invention described exemplary herein can be adequately implemented without any elements, limitations, or restrictions not specifically disclosed herein.

[0065]

[0064] Those skilled in the art will understand that, without relying on excessive experimentation, starting materials, biological materials, reagents, synthesis methods, purification methods, analytical methods, assembly methods, and biological methods other than those specifically exemplified can be used in carrying out the present invention. All known functional equivalents of such materials and methods are intended to be included in the present invention. The terms and expressions used are for illustrative purposes only and not for limiting purposes, and in the use of such terms and expressions, there is no intention to exclude any equivalent of the shown and described features or any part thereof, but it is recognized that various modifications are possible within the scope of the claimed invention. Accordingly, although the present invention is specifically disclosed by preferred embodiments and optional features, it should be understood that modifications and variations of the concepts disclosed herein are accessible to those skilled in the art, and such modifications and variations are considered to be within the scope of the present invention as defined by the appended claims.

Claims

1. In optical particle analyzers, A light source for generating a beam of electromagnetic radiation, A fluid chamber for generating scattered or emitted electromagnetic radiation by flowing a fluid containing particles along the flow direction through a beam of electromagnetic radiation, A light collection system that collects the scattered or emitted electromagnetic radiation from the observation area and directs it towards a detector, A refractive index optimizer operably connected to one or more of the light source, the light collection system, or the detector, in order to control the focus of the beam of electromagnetic radiation in the fluid based on the refractive index of the fluid and to optimize the collection of the electromagnetic radiation by the detector, Equipped with, An optical particle analyzer wherein the refractive index is continuously measured from light scattered from the molecules of the fluid, increasing the amount of electromagnetic radiation reaching the detector and maximizing the signal output of the optical particle analyzer.

2. The optical particle analyzer according to claim 1, wherein the refractive index optimizer includes a beam shaping optical assembly optically positioned between the light source and the fluid chamber, and the refractive index optimizer adjusts the beam shape or beam position of the electromagnetic radiation in the fluid chamber.

3. The optical particle analyzer according to claim 1 or 2, wherein the refractive index optimizer comprises a positioner and / or optical component operably connected to the light source for adjusting the direction of the beam of electromagnetic radiation generated by the light source, and the light source is a laser.

4. The optical particle analyzer according to claim 3, wherein the refractive index optimizer comprises a positioner for moving the laser or for moving the optical component that controls the direction and / or shape of the beam of electromagnetic radiation output by the laser.

5. The optical particle analyzer according to any one of claims 1 to 4, wherein the refractive index optimizer is operably connected to the optical collection system and adjusts the depth of focus of the optical collection system relative to the fluid chamber to correspond to the position of the detector.

6. The optical particle analyzer according to any one of claims 1 to 5, wherein the refractive index optimizer comprises a positioner operably connected to the detector and adjusting the position of the detector relative to the fluid chamber.

7. The optical particle analyzer according to claim 1, wherein the refractive index optimizer comprises a positioner that adjusts the three-dimensional position of one or more of the light source, the collection system, or the detector in one or more of the x, y, or z axes.

8. The optical particle analyzer according to any one of claims 1 to 7, wherein the refractive index optimizer is configured to arrange one or more of the light source, the light collection system, or the detector to maximize the output signal from the detector based on the refractive index of the fluid.

9. The optical particle analyzer according to any one of claims 1 to 8, wherein the refractive index is input by the user to the optical particle analyzer or the refractive index optimizer.

10. The fluid chamber and the refractive index optimizer are further comprising a refractometer operably connected to the fluid chamber and the refractive index optimizer, The optical particle analyzer according to any one of claims 1 to 8, wherein the refractometer measures the refractive index and provides the refractive index to the refractive index optimizer.

11. The system further comprises a processor operably connected to the refractometer and the refractive index optimizer, The aforementioned processor, The focal point is determined based on the measured refractive index. The optical particle analyzer according to claim 10, configured to send control signals to the refractive index optimizer to control one or more of the following: the direction of the beam of electromagnetic radiation, the optical parameters of the light collection system, or the position of the detector for optimizing the collection of the electromagnetic radiation by the detector.

12. The optical particle analyzer according to any one of claims 1 to 11, wherein the refractive index optimizer is configured to provide contrast detection autofocus (CDAF) or phase detection autofocus (PDAF).

13. The optical particle analyzer according to any one of claims 1 to 12, wherein the fluid has a refractive index selected from the range of 1.3 to 1.

6.

14. A laser for generating a beam of electromagnetic radiation, A fluid chamber configured to generate scattered or emitted electromagnetic radiation by flowing a fluid containing particles along the flow direction through the beam of electromagnetic radiation in the observation area, Light collection system and, A detector that communicates optically with the optical collection system, wherein the optical collection system collects the scattered or emitted electromagnetic radiation from the observation area and guides it onto the detector, A beam shaping optical assembly operably connected to the laser, wherein the beam shaping optical assembly includes a beam shaping optical assembly that adjusts the beam shape or beam position of the electromagnetic radiation, An optical particle analyzer equipped with, The beam shaping optical assembly adjusts the beam shape or beam position based on the refractive index of the fluid. The refractive index is obtained from light scattered from the molecules of the fluid, measured continuously. Optical particle analyzer.

15. To measure the refractive index of the fluid, a refractometer is operably connected to the fluid chamber, A processor operably connected to the refractometer and the beamforming optical assembly, It further includes, The aforementioned processor, Based on the refractive index, the optimal beam shape and / or beam position is determined. The optical particle analyzer according to claim 14, which controls the beam shaping optical assembly to optimize the beam shape and / or position.

16. The optical particle analyzer according to any one of claims 14 to 15, wherein the refractive index optimizer is configured to provide contrast-detection autofocus (CDAF) or phase-detection autofocus (PDAF).

17. A method for maximizing the signal output of an optical particle counter, comprising the step of preparing an optical particle analyzer, The aforementioned optical particle analyzer is A laser for generating a beam of electromagnetic radiation, A fluid chamber for generating scattered or emitted electromagnetic radiation by flowing a fluid containing particles along the flow direction through a beam of electromagnetic radiation, A light collection system that collects the scattered or emitted electromagnetic radiation from the observation area and directs it towards a detector, A beam shaping optical assembly operably connected to the laser, Equipped with, The aforementioned method, The steps of causing a fluid to flow through a fluid chamber, The steps include: continuously measuring the refractive index of the fluid in the fluid chamber based on the measurement of light scattered from the molecules of the fluid; The steps include: adjusting the beam shaping optical assembly for the beam shape and / or beam position of the electromagnetic radiation entering the fluid chamber based on the measured refractive index, or adjusting the position of one of the laser, the light collection system, the detector, or any combination thereof based on the measured refractive index, to optimize the depth of focus of the electromagnetic radiation delivered to the electromagnetic radiation entering the fluid chamber and / or the detector; Includes, A method wherein the amount of electromagnetic radiation reaching the detector increases, and the signal output of the photon particle counter is maximized.

18. The method according to claim 17, wherein the refractive index is automatically measured by a refractometer operably connected to the fluid.

19. The method according to claim 18, wherein the refractive index is a time-varying refractive index.

20. The method according to any one of claims 17 to 19, further comprising the step of adjusting the beam shaping optical assembly to the beam shape and / or beam position of the electromagnetic radiation entering the fluid chamber.

21. The method according to any one of claims 17 to 19, comprising the step of adjusting the position of the laser, the light collection system, the detector, or any combination thereof.

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