Differential pressure liquid flow controller

Abstract

The fluid system comprises a capillary, a first temperature sensor, a second temperature sensor, a first pressure sensor, a second pressure sensor, and a processor coupled to these sensors. The processor is configured to execute commands to determine an output using sensor data and fluid parameter data received through an interface coupled to the processor. The processor is coupled to a control device communicating with the capillary and the fluid.

Description

Technology Field

[0001] This patent application claims the benefit of priority of U.S. provisional application No. 63 / 233,029 (Retrieval No. 4270.024PRV), filed on August 13, 2021, the entirety of which is incorporated herein by reference.

[0002] This document relates to a liquid flow controller having improved performance in general, but not limitingly. Background Technology

[0003] Accurately measuring and controlling the flow of liquids or gases is critical in many industrial, commercial, and medical applications. For example, semiconductor manufacturing requires fluid handling equipment where precision is critical for device manufacturing and performance. Flow controllers can provide fluid paths capable of measuring or controlling liquid flow rates.

[0004] Measurement accuracy and control precision can be affected by various factors, including contaminants in the liquid, and irregularities in the fluid path. means of solving the problem

[0005] The subject includes a flow controller configured for accurate flow measurement and control. One example compensates for variations in fluid viscosity and density. Relationships can be established between variables such as temperature, pressure, fluid-intrinsic parameters, and fluid flow rate. A measurement sensor can be configured to detect a first set of physical parameters and enable accurate measurement of a second set of physical parameters.

[0006] The inventors have recognized, among other things, that receiving data corresponding to a fluid system and measuring or controlling fluid flow using a flow controller may be included in the problem to be solved. According to one example, the device may be configured to receive data related to the temperature of the fluid in the capillary, the differential pressure across the capillary, flow information from a flow sensor, and fluid parameter data, and based on this data, the device may determine a flow control setting. When the flow control setting is implemented, this flow control setting changes the fluid flow and provides a negative feedback signal, and by this signal, the device may repeat data collection and readjust the control to change the fluid flow.

[0007] According to one example, the device may be configured to receive data related to the temperature of the fluid in the capillary, the differential pressure across the capillary, and fluid parameter data, and based on this data, the device may determine the fluid flow rate through the capillary. The fluid flow rate may be expressed as a mass flow rate or a volumetric flow rate.

[0008] According to one example, the device may be configured to receive data related to the temperature of the fluid within the capillary, the differential pressure across the capillary, and the measured fluid flow rate. The measured fluid flow rate may be a volumetric flow rate or a mass flow rate. Taking the received data into account, the device may calculate fluid parameters. The fluid parameters may be correlated with the fluid components or selected physical parameters. The fluid parameters may be associated with fluid density, fluid viscosity, or other physical parameters.

[0009] According to one example, the device may be configured to receive data related to the temperature of the fluid within the capillary, the pressure of the fluid within the capillary, and the measured fluid flow rate. The measured fluid flow rate may be a volumetric flow rate or a mass flow rate. Additionally, the device may receive data related to the physical parameters of the fluid within the capillary. Based on the received data, the device may calculate the differential pressure of the fluid within the capillary. The differential pressure may be associated with the measurements of the fluid pressure within the capillary at a first axial position and a second axial position within the capillary.

[0010] Each of these non-restrictive examples may exist alone or be combined with one or more other examples in various permutations or combinations.

[0011] This overview is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or comprehensive description of the invention. Detailed descriptions have been included to provide additional information regarding this patent application. Brief explanation of the drawing

[0012] In drawings that do not necessarily need to be drawn to scale, similar numbers may represent similar components in different drawings. Numbers with different letter suffixes may represent different examples of similar components. The drawings generally illustrate the various embodiments discussed in this document by way of example rather than by way of limitation. Figure 1 is a schematic diagram according to an example of the subject matter. Figure 2 is a flowchart of a method according to an example of the subject matter. Specific details for implementing the invention

[0013] FIG. 1 is a schematic diagram of a system (100) according to an example of the subject matter. The system (100) may be composed of a single package and is sometimes referred to as a device.

[0014] The system (100) is provided with a capillary tube (116) having a lumen through which a fluid can flow. In the illustrated example, the capillary tube (116) is equipped with pressure sensors (110A, 110B), which are also referred to as a first pressure sensor and a second pressure sensor. In various examples, the direction of fluid flow through the capillary tube (116) may be from left to right or from right to left.

[0015] In the illustrated example, the capillary (116) is equipped with a temperature sensor (120A, 120B), which is also referred to as a first temperature sensor and a second temperature sensor. In the drawing, the temperature sensor is coupled to a fitting attached to the ends (first end and second end) of the capillary (116). In other examples, a single temperature sensor (not a dual one) is provided and placed at either end or between the ends. The temperature sensor may have a sensing surface configured to measure the temperature of the capillary wall or the fluid inside the capillary.

[0016] Output signals from pressure sensors (110A, 110B) and temperature sensors (120A, 120B) are coupled to a processor (114). The processor (114) may be equipped with an analog or digital computer having instructions or configurations customized to implement the method described herein. The processor (114) is coupled to an interface (112). The interface (112) may be equipped with a user interface and may have a keyboard, a cursor control device (e.g., a mouse, a trackball, or a touchpad), a display, a printer, a microphone or speaker, or other components that enable interaction between a person and the processor (114) or the system (100). In one example, the interface (112) is equipped with a network interface configured to be coupled to a remote device via a wired or wireless connection.

[0017] In the illustrated example, the processor (114) is coupled to the flow sensor (122). The flow sensor (122) may be located upstream or downstream of the capillary (116). In various examples, the flow sensor (122) is equipped with a mass flow sensor or a volumetric flow sensor. The sensor may provide an output signal accessible to the processor (114), which is a function of the fluid flow through the system (100).

[0018] In the illustrated example, the processor (114) is coupled to the control unit (124). The control unit (124) may be located upstream or downstream of the capillary (116) and may be located proximal or distal to the capillary (116). In various examples, the control unit (124) is equipped with a valve or pump or other hydraulic component having adjustable settings. In the case of a pump with a motor drive, the control unit (124) may be equipped with a signal line through which the processor (114) can set the motor speed and thus the flow rate through the capillary (116). In the drawing, the control unit (124) is illustrated as being connected in series with the capillary (116), but other configurations are also considered. For example, the control unit (124) may be equipped with a bypass or shunt fluid path capable of controlling the flow through the capillary (116). The signal line between the processor (114) and the control device (124) may have a set line capable of controlling the control device (124) and a read line capable of enabling the processor (114) to receive a signal corresponding to the setting of the control device (124).

[0019] FIG. 2 is a flowchart of a method (200) according to an example of the subject matter. In 210, the method (200) includes the step of receiving data. The data may include information regarding temperature from a temperature sensor or pressure from a pressure sensor. Additionally, the received data may include fluid flow information from a flow sensor or device configuration information from a control device associated with a capillary of the system. In some examples, the step of receiving data may include receiving manually entered information regarding physical parameters of a fluid to be used in the system. The data may be received from a user interface or from an interface coupled to a data network or a communication network.

[0020] In 220, the method (200) includes the step of performing a calculation. The calculation may include executing an algorithm according to a stored command or programming. The calculation may include determining a temperature, or determining a pressure or pressure difference. In other examples, the calculation may include determining a flow rate or generating an output signal corresponding to the flow rate, pressure difference, temperature, or physical parameter of the fluid.

[0021] In 230, the method (200) includes the step of providing an output. The step of providing an output may include generating a signal that is humanly perceptible, such as displaying a value or parameter. In various examples, generating an output includes generating a signal configured to operate a control device in a fluid path. For example, the signal may control a fluid flow rate or fluid pressure or other parameters.

[0022] In Poiseuille flow, the liquid moves under the force of a pressure gradient. The gradient can be expressed as differential pressure. Differential pressure is the difference in pressure appearing at the inlet and outlet of a pipe or capillary. Differential pressure is a function of fluid viscosity, volumetric flow rate, and parameters defining the pipe. Fluid viscosity is a function of temperature; therefore, as temperature increases, viscosity decreases.

[0023] The Poiseuille equation is satisfied when the fluid flow is laminar rather than turbulent. Laminar flow is the critical Reynolds number ( Re It is associated with fluid flow of less than ).

[0024] As the flow rate increases, the Reynolds number increases until it reaches a critical value; beyond this value, the flow changes from laminar to transitional flow, and subsequently to turbulent flow. Since the Reynolds number is inversely proportional to viscosity and viscosity decreases as temperature increases, this change is expected to occur at lower flow rates when the liquid temperature is higher. Experimental tests can determine the critical flow rate and the associated critical Reynolds number at various temperatures.

[0025] Fluid flow can be graphically represented in a depiction of a Q-ΔP curve where fluid flow and differential pressure are plotted.

[0026] Theoretical flow and measured flow may differ, and measurements can be calibrated to provide accurate measurements. In some cases, errors in flow rate may be related to viscosity and the difference between theory and measurement. Since viscosity is a function of temperature, accurate temperature measurement provides accurate flow rate measurement.

[0027] Temperature can be measured directly or indirectly. When measuring temperature directly, the sensing surface of the temperature sensor comes into contact with the liquid being measured. When measuring temperature indirectly, the sensing surface of the temperature sensor is attached to measure the wall temperature of the liquid flow tube.

[0028] Indirect measurement can prevent problems arising from direct contact with the liquid under test. For example, direct measurement may become undesirable or impossible due to concerns about contaminants.

[0029] One example of the subject includes directly measuring the liquid temperature during the phenomenon. One example is configured to measure the liquid tube temperature and improve the method to obtain better flow calculations.

[0030] One example of this topic concerns achieving a better understanding of the relationship between flow rate measurement and temperature. For instance, accurate temperature measurement can extend the operating range of a liquid flow controller.

[0031] The liquid temperature can be measured directly at the inlet, outlet, or both of the liquid flow controller (LFC). Additionally, the LFC body temperature can be measured before and after the capillary tube.

[0032] One example considers the temperature-viscosity effect on Q-ΔP DP LFC. Q-ΔP represents the mass flow differential pressure.

[0033] One example includes a configuration that directly measures the liquid temperature before and after the flow resistor, and the body temperature is also measured.

[0034] One example includes a configuration for liquid temperature to directly evaluate the actual temperature versus body temperature affecting the test.

[0035] In various examples of this subject, temperature is associated with measurements at a single temperature sensor site or at a site of multiple temperature sensors. Temperature sensors are attached to the walls of a capillary and can provide a signal associated with the fluid temperature. The sensor sites may be located at axial positions along the length of the capillary, and in various examples, the sensor sites are located at the ends or between the ends. In some examples, the temperature sensor has a sensing surface that is in physical contact with the fluid within the capillary.

[0036] The following equation can help characterize the fluid within a capillary.

[0037]

[0038] This is temperature (B) and viscosity ( μ Express the relationship between ) as a function of integers A and B.

[0039] Theoretical flow rate conversion through calibration.

[0040]

[0041] This represents the relationship between mass flow rate (mass per unit time) and volume flow rate (volume per unit time), where ρ represents density (mass per unit volume).

[0042]

[0043] This equation indicates that the mass flow rate is a function of the differential pressure (across the capillary) and is the product of the ratio of actual density to standard density and the ratio of standard viscosity to actual viscosity.

[0044] It should be noted that there are relationships between specific parameters among the various parameters. For example, viscosity is a fluid parameter affected by temperature. Additionally, differential pressure and temperature are related.

[0045] The onset of transitional flow and turbulence can be observed at different temperatures. In some cases, the critical Re is 2500.

[0046] Features at the capillary inlet, such as wall profiles or irregularities at the edges, can affect the critical Reynolds number. Irregularities can cause disturbances in the inlet flow, thereby reducing the critical Reynolds number. Irregularities can be resolved by removing sharp edges and providing an appropriate profile radius at the capillary inlet. In one example, a filter can be installed upstream of the capillary inlet to capture particles and debris. However, the filter may be placed far enough away so that it does not cause obstruction itself.

[0047] The accuracy of flow rate calculations over the operating range of the LFC is examined using a temperature compensation method that utilizes the following calculations for density and viscosity adjustment. In the following equations, variables A, B, and C are determined by the physical dimensions of the system associated with the capillary.

[0048] viscosity:

[0049] density:

[0050] When the tube is configured in a spiral shape, deformation of the inner diameter of the capillary may occur.

[0051] For example, computational fluid dynamics (CFD) modeling may be applied to the flow path at a selected location, and for example, CFD modeling may be performed downstream of a second pressure sensor to check for turbulence in the flow.

[0052] Ferrule seals can be provided by commercially available ferrules (e.g., those sold by VICI-Valco).

[0053] One example of the disclosed subject matter may be configured for use with various liquids including TEOS (tetraethyl orthosilicate or tetraethoxysilane), water, isopropyl alcohol, methanol, solvents, petroleum products, polymers, and biological fluids.

[0054] In one example, the temperature can be controlled based on an output signal provided by a processor. For example, the temperature of the capillary, the temperature at the inlet end of the capillary, or the temperature at the outlet end of the capillary can be controlled.

[0055] According to the analysis of Q v ΔP, a difference may be revealed when the downstream liquid flow is connected to a vacuum rather than being discharged into the atmosphere.

[0056] In one configuration, the capillary is insulated.

[0057] In one configuration, a (plastic or non-plastic) syringe is used to determine the response time.

[0058] The vacuum pump can be configured to draw in air and expel bubbles. Bubbles in the line can affect the response time.

[0059] In one example, bubbles are introduced into the system, and their effect on response time is measured. For instance, if bubbles are present in the capillary, changes can be monitored.

[0060] Flow rate is a function of temperature.

[0061]

[0062] μ act If =1 and Δ=0.01, then Q1 / Q2= 1±0.01.

[0063] μ act If =0.8 and Δ=0.01, then Q1 / Q2= 1±0.02.

[0064] In one example of the subject matter, the device is configured to operate a component fluidly coupled in series with a capillary. This component may be placed upstream or downstream of the capillary in a fluid path. Additionally, the component may be coupled in a path parallel to the capillary.

[0065] A component, also referred to as a control unit, may be a component capable of managing fluid flow through a capillary. This component may be a fluid pump for pressurizing the fluid. The pump may be a vane pump, a diaphragm pump, a piston pump, or other types of mechanical pumps. In one example, the pump is driven by a motor, and the motor speed determines the pump flow rate or pump pressure, and the motor speed is determined by a signal from a processor. In various examples, the control unit is equipped with a pump having a variable pressure setting or a bypass channel, and a signal transmitted to the control unit enables variation in pump performance. In one example, the control unit is equipped with a valve. The valve may be controlled by a signal from a processor. In one example, the control unit is equipped with a variable orifice, and a signal from the processor may be configured to adjust or select the dimensions of the orifice.

[0066] In one example, the control device is equipped with a thermal device. Accordingly, an output signal from the processor can be configured to increase or decrease the thermal energy delivered to the device.

[0067] In this example, the first temperature sensor and the second temperature sensor are each connected to each end of the capillary. Additionally, the first pressure sensor and the second pressure sensor are also connected to each end of the capillary.

[0068] The interface may include a data input device that can be operated by a user. Examples of the interface may include a cursor control device (e.g., mouse, trackball, touchpad), a keyboard, a touchscreen, and a microphone. Additionally, various examples of the interface may include a printer and a display screen. In one example, the interface includes a network interface configured to communicate data and commands through a wired or wireless connection with a communication network or a data network.

[0069] In one example, the interface enables the input of fluid parameters. Fluid parameters may include physical parameters such as fluid viscosity, fluid density, and fluid composition (including contaminants, particles, and other components).

[0070] In one example, a flow sensor is coupled to a capillary. The flow sensor may include a mass flow sensor, such as a Coriolis sensor. In various examples, the flow sensor may include a mechanical-based sensor (e.g., a turbine flow meter), a pressure-based sensor (e.g., a Pitot tube), a variable-area flow meter, an optical flow meter, an open-channel flow meter, a thermal-mass flow meter, a vortex flow meter, a sonar flow meter, an electromagnetic flow meter, an ultrasonic flow meter, and an optical flow meter. The flow sensor may provide a signal to a processor.

[0071] In one example, a processor receives sensor data (temperature, pressure, flow rate) and executes an algorithm to receive data characterizing fluid parameters. Based on the received data, the processor provides an output signal to a control unit. The output signal can be customized to achieve a specific flow rate or a specific temperature, pressure, or pressure difference associated with the capillary.

[0072] In one example, the processor receives sensor data (temperature and pressure) and executes an algorithm to receive data characterizing fluid parameters. The control element may be omitted or may operate with a fixed setting. Based on the received data, the processor provides an output signal to determine the flow rate. The output signal may be customized to provide an accurate flow rate based on the received data regarding the temperature and differential pressure associated with the capillary. The flow rate may be displayed via a visual indicator.

[0073] In one example, the processor executes an algorithm to receive sensor data (temperature, pressure, and flow rate). Based on the received data, and provided that the control elements associated with the capillary are fixed or non-adjustable, the processor provides an output signal corresponding to selected fluid parameters. The output signal may be customized to provide data representing fluid viscosity, fluid density, particle count, or other parameters. In one example, the output signal may be used for fluid identification or fluid matching.

[0074] In one example, the processor executes an algorithm to receive temperature sensor data, pressure sensor data, and flow rate, and to receive data characterizing fluid parameters. The pressure sensor data may be associated with sensors at the first end and the second end of the capillary, or with some other pressure data. Based on the received data, and provided that the control element associated with the capillary is fixed or non-adjustable, the processor provides an output signal corresponding to the differential pressure. The output signal may be correlated with the differential pressure for one sensed pressure data received by the processor.

[0075] In one example, the processor receives temperature sensor data, differential pressure sensor data, and flow rate, and executes an algorithm to receive data characterizing fluid parameters. The temperature sensor data may be associated with sensors at the first end and the second end of the capillary, or with some other temperature data. Based on the received data, and configured with a fixed or non-adjustable control element associated with the capillary, the processor provides an output signal corresponding to the temperature.

[0076] One objective involves measuring liquid temperature and liquid flow rate. This can be applied to both high and low flow rates. Various approaches can be used to measure liquid temperature. Some of the costs associated with the direct measurement of liquid temperature are also considered. The relationship between flow rate measurement and temperature may be noted. Accurate temperature measurement can expand the operational range for flow rate measurement. One aspect of interest concerns the flow driving the temperature profile.

[0077] An aspect of the subject matter relates to measuring or controlling differential pressure to control fluid flow. Fluid flow is influenced by various factors, including fluid temperature and various physical parameters of the fluid (e.g., viscosity, particle content, density). In one example of the subject matter, a control component is configured to manage fluid flow. The control component may include a pump, valve, reservoir, or other device that affects fluid flow. In one example, an algorithm is executed by a processor to provide flow control, to control a device communicating with the capillary and fluid, or to provide a measurement of a calculated value.

[0078] In one example, the subject includes a device that is calibrated at a first temperature and subsequently operates at another temperature. Examples of the subject provide correlations so that calibration curves can be generated under standard and non-standard conditions.

[0079] Various points to note

[0080] The foregoing description includes reference to the accompanying drawings, which form part of the detailed description. The drawings illustrate specific embodiments in which the present invention may be practiced. These embodiments are also referred to as “Examples” in this specification. Such Examples may include elements in addition to those shown or described. However, the inventors also consider Examples in which only the elements shown or described are provided. Furthermore, the inventors also consider Examples in which any combination or permutation of these elements (or one or more of the elements shown or described) is used in connection with a specific Example (or one or more of the embodiments thereof) or in connection with another Example (or one or more of the embodiments thereof) shown or described in this specification.

[0081] In the event of any discrepancy in usage between this document and any document cited by reference, the usage in this document shall prevail.

[0082] In this document, the article universal in patent documents is used to include one or more than one, regardless of any other instance or use of “at least one” or “one or more.” In this document, the term “or” is used to refer to non-exclusive things, and thus “A or B” includes “A but not B,” “B but not A,” and “A and B” unless otherwise specified. In this document, the terms “comprising” and “in therein” are used as plain synonyms for the terms “comprising” and “in therein,” respectively. Furthermore, in the following claims, the terms “comprising” and “comprising” are open-ended, meaning that a system, device, article, composition, formulation, or process comprising an element in addition to the element enumerated after these terms in a single claim is still considered to be within the scope of that claim. Moreover, in the following claims, terms such as “first,” “second,” and “third,” etc., are used merely as modifiers and are not intended to impose numerical requirements on the subject matter.

[0083] Geometric terms such as "parallel," "perpendicular," "round," or "square" are not intended to require absolute mathematical precision unless otherwise specified in the context. Instead, these geometric terms allow for variations due to manufacturing or equivalent function. For example, if an element is described as "round" or "mostly round," components that are not exactly circular (e.g., components that are slightly rectangular or polygonal) are also included in this description.

[0084] Examples of methods described herein may be realized at least partially by machine or computer. Some examples may include a computer-readable medium or a machine-readable medium encoded with operable instructions to configure an electronic device to perform the method described in the examples. Realizations of such methods may include code such as microcode, assembly language code, higher-level language code, etc. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Additionally, in one example, the code may be substantially stored in one or more volatile, non-transient, or non-volatile physical computer-readable media, for example, during execution or at other times. Examples of such physical computer-readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memory (RAM), read-only memory (ROM), etc.

[0085] The foregoing description is intended to be illustrative, not limiting. For example, the foregoing examples (or one or more embodiments thereof) may be used in combination with one another. Other embodiments may be used when reviewing the foregoing description by those skilled in the art. The abstract is provided to enable the reader to quickly identify the nature of the technical content. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, various features may be grouped together to streamline the disclosure. This should not be interpreted as an intention that any unclaimed disclosed features are essential to any claim. Rather, the subject matter of the invention may be less than all features of the specific disclosed embodiments. Accordingly, the following claims are incorporated into the detailed description as examples or embodiments, and each claim exists as a separate embodiment in itself, and it is taken into account that such embodiments may be combined with one another in various combinations or permutations. The scope of the invention should be determined by reference to the appended claims and the entire scope of equivalents given to such claims.

Claims

Claim 1 A fluid system comprising: a capillary tube having a first end and a second end; a first temperature sensor coupled to the capillary tube; a first pressure sensor disposed at the first end; a second pressure sensor disposed at the second end; a processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, configured to execute a command to determine an output using a first temperature based on the first temperature sensor, a first pressure based on the first pressure sensor, a second pressure based on the second pressure sensor, and fluid parameters received using an interface coupled to the processor; and a control device coupled to the processor and capable of managing fluid flow through the capillary tube using a signal from the processor, the control device comprising a control device coupled to the processor and fluidly communicating with the capillary tube and coupled to a parallel path. Claim 2 In paragraph 1, the control device is a fluid system having at least one of a valve, a pump, and an orifice. Claim 3 In paragraph 1, the interface is a fluid system having a data input device that can be operated by a user. Claim 4 In paragraph 1, the interface is a fluid system having a connection to a network. Claim 5 A fluid system according to claim 1, further comprising a flow sensor coupled to a processor and fluidically coupled to a capillary. Claim 6 In paragraph 5, the flow sensor is a fluid system equipped with a mass flow sensor. Claim 7 A fluid system comprising: a capillary tube having a first end and a second end; a first temperature sensor coupled to the capillary tube; a first pressure sensor disposed at the first end; a second pressure sensor disposed at the second end; a processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, configured to execute a command to determine an output using a first temperature based on the first temperature sensor, a first pressure based on the first pressure sensor, a second pressure based on the second pressure sensor, and fluid parameters received using an interface coupled to the processor, wherein the output is a measured value of the mass flow rate in the capillary tube; and a control device coupled to the processor and capable of managing fluid flow through the capillary tube using a signal from the processor, the control device comprising a control device coupled to the processor and fluidly communicating with the capillary tube and coupled to a parallel path. Claim 8 In paragraph 7, the processor is a fluid system coupled to a display configured to provide a visual indication of the output. Claim 9 In paragraph 7, the interface is a fluid system equipped with a data input device that can be operated by a user. Claim 10 In paragraph 7, the interface is a fluid system having a connection to a network. Claim 11 A fluid system comprising: a capillary tube having a first end and a second end; a first temperature sensor coupled to the capillary tube; a first pressure sensor disposed at the first end; a second pressure sensor disposed at the second end; a processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, configured to execute a command to determine an output using a first temperature based on the first temperature sensor, a first pressure based on the first pressure sensor, a second pressure based on the second pressure sensor, and a flow rate based on a flow rate sensor coupled to the capillary tube, wherein the output is a parameter of the fluid in the capillary tube; and a control device coupled to the processor and capable of managing fluid flow through the capillary tube using a signal from the processor, the control device comprising a control device that is in fluid communication with the capillary tube and coupled to a parallel path. Claim 12 In paragraph 11, the flow sensor is a fluid system equipped with a mass flow sensor. Claim 13 In paragraph 11, the processor is a fluid system coupled to a display configured to provide a visual indication of the output. Claim 14 A fluid system comprising: a capillary tube having a first end and a second end; a first temperature sensor coupled to the capillary tube at the first end; a second temperature sensor coupled to the capillary tube at the second end; a first pressure sensor disposed at the first end; a processor coupled to the first temperature sensor, the first pressure sensor, and the second temperature sensor, configured to execute a command to determine an output using a first temperature based on the first temperature sensor, a first pressure based on the first pressure sensor, fluid parameters received using an interface coupled to the processor, and a flow rate received from a flow rate sensor in fluid communication with the capillary tube, wherein the output is a differential pressure associated with the first pressure; and a control device coupled to the processor and capable of managing fluid flow through the capillary tube using a signal from the processor, wherein the control device is in fluid communication with the capillary tube and coupled to a parallel path. Claim 15 In paragraph 14, the interface is a fluid system equipped with a data input device that can be operated by a user. Claim 16 In paragraph 14, the interface is a fluid system having a connection to a network. Claim 17 In paragraph 14, the flow sensor is a fluid system equipped with a mass flow sensor. Claim 18 In paragraph 14, the flow sensor is a fluid system equipped with a volumetric flow sensor.

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