Differential pressure liquid flow controller

Abstract

The fluid system includes a capillary tube, first and second temperature sensors, first and second pressure sensors, and a processor coupled to the sensors. The processor is configured to execute instructions to use the sensor data and to determine an output using fluid parameter data received via an interface coupled to the processor. The processor is coupled to a controller in fluid communication with the capillary tube.

Description

[Technical Field]

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

[0002] This document generally relates to, but not limited to, liquid flow controllers with improved performance. [Background technology]

[0003] Precisely measuring and controlling the flow rate of liquids or gases is crucial in many industrial, commercial, and medical applications. For example, semiconductor manufacturing requires fluid handling equipment where precision is critical to the manufacturing and performance of the devices. Flow controllers can provide channels through which the flow rate of liquids can be measured or controlled.

[0004] Measurement accuracy and control precision can be affected by many factors, including contaminants in the liquid and irregularities in the flow path. [Overview of the project] [Means for solving the problem]

[0005] This subject includes flow controllers 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-specific parameters, and fluid flow rate. Measuring sensors may be configured to sense 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 the problems to be solved may include receiving data corresponding to a fluid system and measuring or controlling the fluid flow rate using a flow controller. For example, the device can be configured to receive the temperature of the fluid in the capillary, the differential pressure across the capillary, flow rate information from a flow sensor, and fluid parameter data, based on this data the device can determine flow control settings. Once implemented, the flow control settings change the fluid flow rate and provide a negative feedback signal, which allows the device to repeat data collection and readjust the control to change the fluid flow rate.

[0007] For example, the device can be configured to receive data on 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 can determine the fluid flow rate through the capillary. The fluid flow rate can be expressed as mass flow rate or volumetric flow rate.

[0008] For example, the device can be configured to receive data related to the temperature of the fluid in the capillary, the differential pressure across the capillary, and the measured fluid flow rate. The measured fluid flow rate can be either volumetric or mass flow rate. Considering the received data, the device can calculate fluid parameters. Fluid parameters can be correlated with the fluid's components or selected physical parameters. Fluid parameters can be associated with fluid density, fluid viscosity, or other physical parameters.

[0009] For example, the device can be configured to receive data related to the temperature of the fluid in the capillary, the fluid pressure in the capillary, and the measured fluid flow rate. The measured fluid flow rate can be either volumetric or mass flow rate. In addition, the device can receive data related to the physical parameters of the fluid in the capillary. Taking the received data into consideration, the device can calculate the differential pressure of the fluid in the capillary. The differential pressure can be associated with the measured fluid pressure in the capillary at a first axial position and a second axial position in the capillary.

[0010] Each of these non-restrictive examples can stand on its own or can be combined with one or more of the other examples in various permutations or combinations.

[0011] This summary is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive description of the invention. A more detailed description is intended to provide further information relating to this patent application.

[0012] In drawings that are not necessarily drawn to scale, similar numbers may describe similar components in different drawings. Similar numbers with different letter prefixes may represent different instances of similar components. Drawings are generally illustrative examples, not limiting, of the various embodiments discussed in this document. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram illustrating an example of this topic. [Figure 2] This is a flowchart illustrating an example of the method described in this subject. [Modes for carrying out the invention]

[0014] Figure 1 is a schematic diagram of system 100, an example of this subject. System 100 can be configured in a single package, sometimes referred to as a device.

[0015] System 100 includes a capillary tube 116 having a lumen through which a fluid can flow. Pressure sensors 110A and 110B, sometimes referred to as a first pressure sensor and a second pressure sensor in the illustrated example, are attached to the capillary tube 116. The direction of fluid flow can be from left to right or right to left through the capillary tube 116 in various examples.

[0016] In the illustrated example, temperature sensors 120A and 120B, sometimes referred to as the first and second temperature sensors, are mounted on the capillary tube 116. In the figure, the temperature sensors are coupled to fixtures attached to the ends (first and second ends) of the capillary tube 116. In other examples, a single temperature sensor (rather than a dual one) is provided and positioned 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 tube.

[0017] The output signals from pressure sensors 110A and 110B and temperature sensors 120A and 120B are coupled to processor 114. Processor 114 may include an analog or digital computer having instructions or configurations tailored to implement the method described herein. Processor 114 is coupled to interface 112. Interface 112 may include a user interface and may have a keyboard, a cursor control device (such as a mouse, trackball, or touchpad), a display, a printer, a microphone or speaker, or other components that enable human interaction with processor 114 or system 100. In one example, interface 112 may include a network interface configured to couple to a remote device via a wired or wireless connection.

[0018] In the illustrated example, the processor 114 is coupled to a flow sensor 122. The flow sensor 122 can be upstream or downstream of the capillary 116. In various examples, the flow sensor 122 includes a mass flow sensor or a volumetric flow sensor. The sensor can provide an output signal that is accessible to the processor 114, and the signal is a function of the fluid flow rate through the system 100.

[0019] In the illustrated example, the processor 114 is coupled to a control unit 124. The control unit 124 can be upstream or downstream of the capillary 116 and can be proximal or distal to the capillary 116. In various examples, the control unit 124 includes a valve with adjustable settings, or a pump, or other hydraulic components. In the case of a pump having a motor drive, the control unit 124 can include a signal line through which the processor 114 can set the motor speed and thus the flow rate through the capillary 116. In the figure, the control unit 124 is depicted in series connection with the capillary 116, but other configurations are also conceivable. For example, the control unit 124 can include a bypass or shunt fluid passage through which the flow through the capillary 116 can be adjusted. The signal line between the processor 114 and the control unit 124 can include a setting line by which the control unit 124 can be controlled, and can include a read line by which the processor 114 can receive a signal corresponding to the setting of the control 124.

[0020] Figure 2 shows a flowchart of a method 200 according to an example of the present subject matter. At 210, method 200 includes the step of receiving data. The data can include information regarding temperature from a temperature sensor or pressure from a pressure sensor. In addition, the received data can include fluid flow rate information from a flow sensor, or device configuration information from a control device in communication with the capillary of the system. In some examples, the step of receiving data can include the step of receiving manually entered information regarding the physical parameters of the fluid used in the system. The data can be received from a user interface, or from an interface coupled to a data network or a communication network.

[0021] At 220, method 200 includes the step of performing a calculation. The calculation can include the step of executing an algorithm according to stored instructions or programming. The calculation can include determining a temperature, determining a pressure or a pressure difference. In other examples, the calculation can include determining a flow rate, or generating an output signal corresponding to a flow rate, a pressure difference, a temperature, or a physical parameter of the fluid.

[0022] At 230, method 200 includes the step of providing an output. The step of providing an output can include the step of generating a signal perceptible to humans, such as the step of displaying a value or a parameter. In various examples, the step of generating an output includes the step of generating a signal configured to operate a control device within a fluid passageway. The signal can control, for example, a fluid flow rate or a fluid pressure or another parameter.

[0023] In Poiseuille flow, a liquid moves under the force of a pressure gradient. This gradient can be expressed by differential pressure. Differential pressure is the pressure difference observed at the inlet and outlet of a pipe or capillary tube. It is a function of fluid viscosity, volumetric flow rate, and parameters defining the pipe. Fluid viscosity is a function of temperature, thereby increasing the temperature decreases viscosity.

[0024] Poiseuille's equations are satisfied when the fluid flow is laminar rather than turbulent. Laminar flow is associated with fluid flow below the critical Reynolds number (Re).

[0025] As the flow rate increases, the Reynolds number increases until it reaches a critical value beyond which laminar flow changes to transitional flow and then turbulent flow. Since the Reynolds number is inversely proportional to viscosity, and viscosity decreases with increasing temperature, such changes are expected to occur at lower flow rates at higher liquid temperatures. Experimental tests can determine the critical Reynolds number associated with threshold flow rates at various temperatures.

[0026] Fluid flow can be graphically represented by plotting a Q-ΔP curve in which the fluid flow and differential pressure are plotted.

[0027] Theoretical and measured flow rates may differ, and instrumentation can be calibrated to provide accurate measurements. In some cases, flow rate errors may be related to viscosity and differences between theory and measurement. Since viscosity is a function of temperature, accurate temperature measurements provide accurate flow rate measurements.

[0028] Temperature can be measured directly or indirectly. When measuring temperature directly, the sensing surface of the temperature sensor is in 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.

[0029] Indirect measurement can avoid the complexities that arise from direct contact with the liquid being tested. For example, concerns about contaminants may make direct measurement undesirable or impossible.

[0030] One example of this subject involves directly measuring the liquid temperature during development. Another example is configured to measure the temperature of the liquid tube and improve the method to obtain better flow rate calculations.

[0031] One example of this subject is aimed at achieving a better understanding of the relationship between flow rate measurements and temperature. For instance, accurate temperature measurements can extend the operating range of a liquid flow controller.

[0032] The liquid temperature can be measured directly at the inlet, outlet, or both of the inlet and outlet of the liquid flow controller (LFC). In addition, the LFC temperature can be measured before and after the capillary tube.

[0033] One example considers the temperature effect of viscosity in a Q-deltP DP LFC. Q-deltP refers to the mass flow differential pressure.

[0034] One example includes a configuration for measuring liquid temperature directly before and after a flow resistor, and body temperature was also measured.

[0035] One example includes a configuration for liquid temperature to directly assess whether actual temperature versus body temperature affects the test.

[0036] In various examples of this subject, temperature is associated with measurements at a single temperature sensor location or at multiple temperature sensor locations. Temperature sensors are mounted on the capillary wall and can provide signals related to fluid temperature. Sensor locations can be axially positioned along the length of the capillary, and in various examples, sensor locations are at the ends or between the ends. In some examples, temperature sensors have a sensing surface that is in physical contact with the fluid within the capillary.

[0037] The following equation is useful in characterizing the fluid inside a capillary.

[0038]

number

[0039] μ act. =f(T)=Ae B / T

[0040] This expresses the relationship between temperature (B) and viscosity μ as a function of constants A and B.

[0041] Calibration-based theoretical flow rate conversion. Q m =ρQ v

[0042] This represents the relationship between mass flow rate (mass per unit time) and volumetric flow rate (volume per unit time), where ρ represents density (mass per unit volume).

[0043]

number

[0044] This equation shows that the mass flow rate is a function of the differential pressure (across the capillaries), the product of the ratio of the actual density to the standard density, and the product of the ratio of the standard viscosity to the actual viscosity.

[0045] It should be noted that there are relationships between certain parameters. For example, viscosity is a fluid parameter that is affected by temperature. In addition, differential pressure and temperature are related.

[0046] Transitional and turbulent flow can occur at various temperatures. In some cases, the critical temperature (Re) is 2500.

[0047] Features such as irregularities in the wall contour or edges at the capillary inlet can affect the critical Reynolds number. Irregularities can introduce turbulence into the inlet flow, thereby lowering the critical Reynolds number. Irregularities can be addressed by removing sharp edges and providing an appropriate contour radius at the capillary inlet. In one example, a filter can be placed upstream of the capillary inlet to capture particles and debris. However, the filter can be placed far enough away so as not to cause disturbance by itself.

[0048] The accuracy of flow rate calculations across the entire operating range of the LFC is examined using a temperature compensation method that utilizes the following calculations to adjust density and viscosity. In the following equations, variables A, B, and C are determined by the physical dimensions of the system and are here associated with the capillary. viscosity:

[0049]

number

[0050] density:

[0051]

number

[0052] When a tube is constructed in a spiral shape, deformation of the inner diameter of the capillary tube may be observed.

[0053] In one example, computational fluid dynamics (CFD) modeling can be applied to the flow path at a selected location. For instance, CFD modeling is performed downstream of a second pressure sensor to check for turbulence in the flow.

[0054] A ferrule seal can be provided using a commercially available ferrule (such as those offered by VICI-Valco).

[0055] One example of the disclosed subject matter can be configured to be used with various liquids including TEOS (tetraethyl orthosilicate or tetraethoxysilane), water, isopropyl alcohol, methanol, solvents, petroleum products, polymers, and biological fluids.

[0056] 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.

[0057] Analysis of QvΔP can reveal differences when the downstream liquid flow is coupled to a vacuum rather than being discharged to the atmosphere.

[0058] In one configuration, the capillary tube is insulated.

[0059] In one configuration, a syringe (plastic or non - plastic) is used to determine the response time.

[0060] The vacuum pump can be configured to suck air and remove bubbles. Bubbles in the line can sometimes affect the response time.

[0061] In one example, bubbles are introduced into the system and the effect on the response time is measured. For example, if there are bubbles in the capillary, changes can be monitored.

[0062] The flow rate is a function of temperature. Q=f(ΔP)·(μ std / μ act ) Q1=f(ΔP)·(μ std / μ act )<除 Q2=f(ΔP)·(μ std / (μ act +Δ)) Q1 / Q2=(μ act +Δ) / μ act =1+Δ / μ It should be noted that for the tags std , act , std , act , std , act , act , act which seem to be some kind of special notations in the original text, they are kept as they are in the translation as per the requirement. There might be some inaccuracies in the translation due to the lack of clear context for these notations. If they are chemical or physical constants etc., it might be beneficial to have more background information for a more accurate translation. Also, in the original text, there is a tag <除 which seems incorrect, it's kept as is in the translation for now, but it should be corrected in the original if possible.act μ act If Q1 / Q2 = 1 and Δ = 0.01, then Q1 / Q2 = 1 ± 0.01 μ act If =0.8 and Δ=0.01, then Q1 / Q2=1±0.02

[0063] In one example of this subject, the device is configured to operate a component fluidly coupled in series with a capillary. The component can be located in a fluid passage upstream or downstream of the capillary. In addition, the component can be coupled along a path parallel to the capillary.

[0064] A component sometimes called a control unit can be a component that enables the management of fluid flow through a capillary. The component can be a fluid pump for pressurizing the fluid. The pump can 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 whose motor speed determines the pump flow rate or pump pressure, and whose motor speed is determined by a signal from a processor. In various examples, the control unit includes a pump with a variable pressure setting or bypass channel, and the signal sent to the control unit allows for variations in pump performance. In one example, the control unit includes a valve, which can be controlled by a signal from a processor. In one example, the control unit includes a variable orifice, and the signal from the processor can be configured to adjust or select the size of the orifice.

[0065] In one example, the control unit includes a thermal device. Therefore, the output signal from the processor can be configured to increase or decrease the thermal energy delivered to the device.

[0066] In this example, the first temperature sensor and the second temperature sensor are each connected to the respective ends of the capillary tube. In addition, the first pressure sensor and the second pressure sensor are also connected to the respective ends of the capillary tube.

[0067] An interface can include user-operable data input devices. Examples of interfaces can include cursor control devices (such as mice, trackballs, and touchpads), keyboards, touchscreens, and microphones. In addition, various examples of interfaces can include printers and display screens. In one example, the interface includes a network interface configured to communicate data and commands via a wired or wireless connection to a communication network or data network.

[0068] In one example, the interface allows 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).

[0069] In one example, the flow sensor is coupled to a capillary tube. The flow sensor may include mass flow sensors such as Coriolis sensors. In various examples, the flow sensor may include mechanically based sensors (such as turbine flow meters), pressure-based sensors (such as Pitot tubes), variable-area flow meters, optical flow meters, open-channel flow meters, thermal mass flow meters, vortex flow meters, sonar flow meters, electromagnetic flow meters, ultrasonic flow meters, and optical flow meters. The flow sensor can provide a signal to a processor.

[0070] In one example, the 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 the control unit. The output signal can be adjusted to achieve a specific flow rate or to establish a specific temperature, pressure, or pressure difference related to the capillary.

[0071] In one example, the processor receives sensor data (temperature and pressure) and executes an algorithm to receive data characterizing fluid parameters. Control elements can be omitted or operated in a fixed configuration. Based on the received data, the processor provides an output signal to determine the flow rate. The output signal can be adjusted to provide an accurate flow rate based on the received data regarding the temperature and pressure difference related to the capillary. The flow rate can be indicated by a visual display.

[0072] In one example, the processor executes an algorithm to receive sensor data (temperature, pressure, flow rate). Based on the received data, the processor provides an output signal corresponding to selected fluid parameters, provided that the system is configured with fixed or immovable control elements associated with the capillary. The output signal can be adjusted to provide data indicating fluid viscosity, fluid density, particle count, or another parameter. In one example, the output signal can be used for fluid identification or fluid matching.

[0073] In one example, the processor receives temperature sensor data, pressure sensor data, and flow rate, and executes an algorithm to receive data characterizing the fluid parameters. The pressure sensor data can be associated with a sensor at the first end of the capillary, a sensor at the second end of the capillary, or some other pressure data. Based on the received data, the processor provides an output signal corresponding to the differential pressure, if configured with fixed or immovable control elements associated with the capillary. The output signal can be correlated with the differential pressure relative to one sensed pressure data received by the processor.

[0074] In one example, the processor receives temperature sensor data, differential pressure sensor data, and flow rate, and executes an algorithm to receive data characterizing the fluid parameters. The temperature sensor data can be associated with a sensor at the first end of the capillary, a sensor at the second end of the capillary, or any other temperature data. Based on the received data, the processor provides an output signal corresponding to the temperature, if configured with fixed or immovable control elements associated with the capillary.

[0075] One objective involves measuring liquid temperature and liquid flow rate. This may apply to both high and low flow rates. Various methods can be used to measure liquid temperature. Some of the costs associated with direct measurement of liquid temperature should also be considered. A relationship may be observed between flow rate and temperature. Accurate temperature measurement can extend the operating range of flow rate measurement. One interesting aspect concerns the flow driving the temperature profile.

[0076] One aspect of this subject relates to measuring or controlling differential pressure to control a flow. Fluid flow is influenced by many factors, including various physical parameters of the fluid (such as viscosity, particle content, and density) and fluid temperature. In one example of this application, a control component is configured to manage the fluid flow. The control component may include a pump, valve, reservoir, or other device that affects the fluid flow. In one example, an algorithm is executed by a processor to provide fluid control, control a device communicating with a capillary and the fluid, or provide a measured value of a calculated value.

[0077] In one example, this subject includes a device that is calibrated at a first temperature and then operated at another temperature. This example provides interrelationships that enable the generation of calibration curves under standard and non-standard conditions.

[0078] Various precautions The above description includes references to the accompanying drawings, which form part of the detailed description. The drawings illustrate specific embodiments in which the present invention may be carried out. These embodiments are also referred to herein as “examples.” Such examples may include elements in addition to those illustrated or described. However, the inventors also intend examples in which only those illustrated or described elements are provided. Furthermore, the inventors also intend examples in which any combination or permutation of those illustrated or described elements (or one or more embodiments thereof) is used in reference to a particular example (or one or more embodiments thereof) or in reference to other examples (or one or more embodiments thereof) illustrated or described herein.

[0079] In the event of any conflict between the usage described in this document and any document incorporated by reference, the usage described in this document shall prevail.

[0080] In this document, the terms “a” or “an” are used to include one or more, as is common in patent documents, independently of any other instances or uses of “at least one” or “one or more.” In this document, the term “or” is used to refer to non-exclusive or, unless otherwise indicated, such as “A or B” including “A but not B,” “B but not A,” and “A and B.” In this document, the terms “including” and “in which” are used as plain English equivalents of the terms “equipped with” and “wherein.” Furthermore, in the appended claims, the terms “including” and “equipped with” are unrestrictive; that is, any system, device, article, compound, formulation, or process that includes elements in addition to those listed after such terms in a claim is still considered to be within the scope of that claim. In addition, in the appended claims, terms such as “first,” “second,” and “third” are used merely as labels and are not intended to impose numerical requirements on their subjects.

[0081] Geometric terms such as "parallel," "perpendicular," "circular," or "square" are not intended to require absolute mathematical precision unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent function. For example, if an element is described as "circular" or "nearly circular," components that are not exactly circular (e.g., slightly rectangular or polygonal) are still included in this description.

[0082] The examples of methods described herein can be implemented at least partially by machine or computer. Some examples may include computer-readable or machine-readable media encoded with instructions that can be used to configure an electronic device to perform the methods described in the examples above. Implementations of such methods may include code such as microcode, assembly language code, or high-level language code. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Furthermore, in one example, the code may be tangibly stored on one or more volatile, non-temporary, or non-volatile tangible computer-readable media during execution or at other points in time. Examples of these tangible computer-readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact discs and digital video discs), magnetic cassettes, memory cards or memory sticks, random access memory (RAM), read-only memory (ROM), and the like.

[0083] The above description is illustrative and not restrictive. For example, the examples (or one or more embodiments thereof) described above may be used in combination with each other. Other embodiments may be used by those skilled in the art who have considered the above description. The abstract is provided to enable readers to quickly confirm the nature of the technical disclosure. The abstract is submitted with the understanding that it is not to be used to interpret or limit the claims or their meaning. Also, in the above detailed description, various features may be grouped together to streamline the disclosure. This should not be interpreted as meaning that any disclosed features not claimed are essential to any claim. Rather, the subject matter of the invention may lie in fewer features than all the features of a particular disclosed embodiment. Accordingly, the appended claims are intended to ensure that each claim is incorporated into the detailed description as an example or embodiment, independently of itself as a distinct embodiment, and that such embodiments may be combined with each other in various combinations or substitutions. The scope of the invention should be determined by referring to the appended claims together with the entire scope of equivalents to which such claims are entitled. [Explanation of symbols]

[0084] 100 Systems 110A pressure sensor 110B Pressure Sensor 112 Interfaces 114 processors 116 Capillary 120A temperature sensor 120B Temperature Sensor 122 Flow Sensor 124 Control Unit

Claims

1. A capillary tube having a first end and a second end, A first temperature sensor coupled to the capillary tube, A first pressure sensor positioned at the first end, A second pressure sensor is positioned at the second end, A processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, wherein the processor The first temperature based on the first temperature sensor, The first pressure based on the first pressure sensor, The second pressure based on the second pressure sensor, A fluid parameter, the fluid parameter is received using an interface coupled to the processor, and The processor is configured to execute instructions that determine the output using the processor, the processor being coupled to a control unit that is in fluid communication with the capillary, the fluid parameters including at least one parameter selected from fluid viscosity, fluid density, and fluid composition, and the control unit including a bypass or shunt fluid passage capable of regulating the flow through the capillary. Equipped with, The first temperature sensor has a sensing surface configured to measure the temperature of the capillary wall or the fluid inside the capillary, A fluid system in which the signal lines between the processor and the control unit include a setting line from which the control unit can be controlled, and a reading line from which the processor can receive signals corresponding to the settings of the control unit.

2. The fluid system according to claim 1, wherein the control unit includes at least one of a valve, a pump, and an orifice.

3. The fluid system according to claim 1, wherein the interface includes a user-operable data input device.

4. The fluid system according to claim 1, wherein the interface includes connection to a network.

5. The fluid system according to claim 1, further comprising a flow sensor coupled to the processor and fluid-coupled to the capillary tube.

6. The fluid system according to claim 5, wherein the flow sensor includes a mass flow sensor.

7. A capillary tube having a first end and a second end, A first temperature sensor coupled to the capillary tube, A first pressure sensor positioned at the first end, A second pressure sensor is positioned at the second end, A processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, wherein the processor The first temperature based on the first temperature sensor, The first pressure based on the first pressure sensor, The second pressure based on the second pressure sensor, A fluid parameter, the fluid parameter is received using an interface coupled to the processor, and The processor is configured to execute instructions that determine the output using the output corresponding to the measured mass flow rate in the capillary tube. Equipped with, The processor is coupled to a control unit that is in fluid communication with the capillary, the fluid parameters include at least one parameter selected from fluid viscosity, fluid density, and fluid composition, and the control unit includes a bypass or shunt fluid passage capable of regulating the flow through the capillary. The first temperature sensor has a sensing surface configured to measure the temperature of the capillary wall or the fluid inside the capillary, A fluid system in which the signal lines between the processor and the control unit include a setting line from which the control unit can be controlled, and a reading line from which the processor can receive signals corresponding to the settings of the control unit.

8. The fluid system according to claim 7, wherein the processor is coupled to a display configured to provide a visible display of the output.

9. The fluid system according to claim 7, wherein the interface includes a user-operable data input device.

10. The fluid system according to claim 7, wherein the interface includes connection to a network.

11. A capillary tube having a first end and a second end, A first temperature sensor coupled to the capillary tube, A first pressure sensor positioned at the first end, A second pressure sensor is positioned at the second end, A processor coupled to the first temperature sensor, the first pressure sensor, and the second pressure sensor, wherein the processor The first temperature based on the first temperature sensor, The first pressure based on the first pressure sensor, The second pressure based on the second pressure sensor, The flow rate based on the flow sensor connected to the capillary tube and The processor is configured to execute instructions that determine the output using the parameters of the fluid in the capillary tube, and the output corresponds to the parameters of the fluid in the capillary tube. Equipped with, The processor is coupled to a control unit that is in fluid communication with the capillary, the fluid parameters include at least one parameter selected from fluid viscosity, fluid density, and fluid composition, and the control unit includes a bypass or shunt fluid passage capable of regulating the flow through the capillary. The first temperature sensor has a sensing surface configured to measure the temperature of the capillary wall or the fluid inside the capillary, A fluid system in which the signal lines between the processor and the control unit include a setting line from which the control unit can be controlled, and a reading line from which the processor can receive signals corresponding to the settings of the control unit.

12. The fluid system according to claim 11, wherein the flow sensor includes a mass flow sensor.

13. The fluid system according to claim 11, wherein the processor is coupled to a display configured to provide a visible display of the output.

14. A capillary tube having a first end and a second end, A first temperature sensor is coupled to the capillary tube at the first end, A second temperature sensor is coupled to the capillary tube at the second end, A first pressure sensor positioned at the first end, A processor coupled to the first temperature sensor, the first pressure sensor, and the second temperature sensor, wherein the processor The first temperature based on the first temperature sensor, The first pressure based on the first pressure sensor, A fluid parameter, wherein the fluid parameter is received using an interface coupled to the processor, A flow rate, wherein the flow rate is received from a flow sensor that is in fluid communication with the capillary tube, and The processor is configured to execute instructions that determine the output using the differential pressure associated with the first pressure, and the output corresponds to the differential pressure associated with the first pressure. Equipped with, The processor is coupled to a control unit that is in fluid communication with the capillary, the fluid parameters include at least one parameter selected from fluid viscosity, fluid density, and fluid composition, and the control unit includes a bypass or shunt fluid passage capable of regulating the flow through the capillary. The first temperature sensor and the second temperature sensor each have a sensing surface configured to measure the temperature of the capillary wall or the fluid inside the capillary, A fluid system in which the signal lines between the processor and the control unit include a setting line from which the control unit can be controlled, and a reading line from which the processor can receive signals corresponding to the settings of the control unit.

15. The fluid system according to claim 14, wherein the interface includes a user-operable data input device.

16. The fluid system according to claim 14, wherein the interface includes connection to a network.

17. The fluid system according to claim 14, wherein the flow sensor includes a mass flow sensor.

18. The fluid system according to claim 14, wherein the flow sensor includes a volumetric flow sensor.

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