Pressure transducers having improved operating pressure ranges

Abstract

To provide pressure transducers.SOLUTION: Disclosed example pressure transducers include: a pressure housing comprising a first cavity; a fluid input line configured to provide a fluid to the first cavity; a first pressure measurement assembly of a first type configured to output a first measurement signal based on pressure of the fluid in the first cavity; a second pressure measurement assembly of a second type configured to output a second measurement signal based on the pressure of the fluid in the first cavity; and a controller configured to determine the pressure of the fluid in the first cavity based on the first measurement signal when the pressure is within a first range, and determine the pressure of the fluid in the first cavity based on the second measurement signal when the pressure is within a second range.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] [Related Applications] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 596,034, filed on November 3, 2024, entitled "PRESSURE TRANSDUCERS HAVING IMPROVED OPERATING PRESSURE RANGES". The entire disclosure of U.S. Provisional Patent Application No. 63 / 596,034 is hereby incorporated by reference and made a part of this specification.

[0002] The present disclosure generally relates to pressure transducers, and more specifically, to pressure transducers having improved operating pressure ranges.

Background Art

[0003] A pressure sensor or pressure transducer measures the pressure of a fluid input to the sensor that is compared to a reference pressure. A pressure sensor can be constructed to compare the input pressure to a fixed reference pressure or a variable reference pressure.

Summary of the Invention

[0004] A pressure transducer having an improved operating pressure range is disclosed, substantially as shown by at least one of the drawings and described in connection therewith, as more fully set forth in the claims.

[0005] These features, aspects, and advantages of the present disclosure, as well as other features, aspects, and advantages, will be better understood when the following detailed description is read in conjunction with the accompanying drawings, in which like reference numerals represent like parts throughout the drawings.

Brief Description of the Drawings

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Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

[0011] The drawings are not necessarily to scale. Where appropriate, like or identical reference numerals are used to refer to like or identical components.

[0012] Reference is now made to the embodiments shown in the drawings and described herein using specific terms for the purpose of facilitating an understanding of the principles of the claimed technology and presenting its presently understood best mode of operation. However, it will be understood that this is not intended to limit the scope of the claimed technology, and that such changes and further modifications in the illustrated devices, and such further applications of the principles of the claimed technology as described herein, would typically occur to one of ordinary skill in the art related to the claimed technology.

[0013] Conventional pressure gauges use pressure measurement assemblies that have high accuracy over a certain range. However, conventional pressure gauges may have an insufficient operating range and / or the accuracy may vary over a partial range of the operating range. Additionally, conventional pressure gauges may be unstable over the life of the sensor.

[0014] The disclosed exemplary pressure transducer includes a plurality of different types of pressure measurement assemblies (also referred to as pressure sensors) that provide an extended pressure measurement range with low error and high stability. In some examples, the pressure transducer includes a first pressure measurement assembly of a first type (e.g., a microelectromechanical pressure sensor) and a second pressure measurement assembly of a second type (e.g., a capacitance diaphragm gauge). The control circuit unit can be used to select which of the plurality of pressure measurement assemblies to use for pressure measurement. In some examples, different types of pressure measurement assemblies are selected for pressure measurement over different pressure measurement ranges due to different error factors present in different pressure measurement assemblies at different pressures.

[0015] In some examples, the ranges in which each of the pressure measurement assemblies results in less than a threshold error partially overlap, and one of the pressure measurement assemblies can be used to calibrate the other of the pressure measurement assemblies. For example, if one type of pressure measurement assembly is prone to drift or other instabilities over time, the other type of pressure measurement assembly can be used to recalibrate the pressure measurement assembly to compensate for the drift or instability.

[0016] The disclosed exemplary pressure transducer includes a pressure housing having a first cavity, a fluid input line configured to supply fluid to the first cavity, a first pressure measurement assembly of a first type configured to output a first measurement signal based on the pressure of the fluid within the first cavity, a second pressure measurement assembly of a second type configured to output a second measurement signal based on the pressure of the fluid within the first cavity, and a controller configured to determine the pressure of the fluid within the first cavity based on the first measurement signal when the pressure is within a first range and to determine the pressure of the fluid within the first cavity based on the second measurement signal when the pressure is within a second range.

[0017] In some exemplary pressure transducers, the first pressure measurement assembly includes a microelectromechanical pressure sensor. In some exemplary pressure transducers, the microelectromechanical pressure sensor includes a resonant pressure sensor formed by trench etching.

[0018] In some exemplary pressure transducers, the second pressure sensor includes a capacitance diaphragm gauge. In some exemplary pressure transducers, the pressure housing includes a second cavity separated from the first cavity by a measurement diaphragm, and the second pressure measurement assembly is disposed within the second cavity. Some exemplary pressure transducers further include a heater configured to heat at least the first cavity and the second cavity based on a target temperature. In some exemplary pressure transducers, the first pressure measurement assembly is disposed at least partially within the first cavity or at least partially within the second cavity.

[0019] In some exemplary pressure transducers, the first range and the second range include at least from 0.01 Torr (about 1.3 Pa) to 100 Torr (about 1.3x10 4 Pa). In some exemplary pressure transducers, the first range and the second range include at least from 0.1 Torr (about 1.3x10 Pa) to 1000 Torr (about 1.3x10 5 Pa). In some exemplary pressure transducers, the first range and the second range include at least from 0.01 Torr (about 1.3 Pa) to 1000 Torr (about 1.3x10 5 Pa).

[0020] In some exemplary pressure transducers, the controller is configured to calibrate one of the first pressure measurement assembly or the second pressure measurement assembly based on the output of the other of the first pressure measurement assembly or the second pressure measurement assembly when the pressure of the fluid is within a predetermined range. In some exemplary pressure transducers, the first range partially overlaps the second range, and the predetermined range is at least partially within the overlapping portion of the first range and the second range. In some exemplary pressure transducers, the first range partially overlaps the second range.

[0021] FIG. 1 is a block diagram of an exemplary process control system 100 including a pressure transducer 102. The exemplary process control system 100 of FIG. 1 includes a process chamber 104, and the pressure transducer 102 is fluidly coupled to the process chamber 104 via a fluid input line 106 to measure the pressure of the process chamber 104.

[0022] The exemplary process chamber 104 can receive one or more inputs, such as process feed materials, via a corresponding number of supply lines 108a, 108b that can be controlled via mass flow controllers 110a, 110b.

[0023] The exemplary system 100 can include a vacuum pump 112 or other pressure control pump, and a valve 114 that controls the flow rate between the vacuum pump 112 and the process chamber 104. The valve 114 can be controlled by a controller 116, a computing device, and / or any other control technique to maintain the pressure within the process chamber 104 within a desired range. The exemplary pressure transducer 102 is communicatively coupled to the controller 116 and supplies pressure feedback to the controller 116 (e.g., for use in a pressure control loop). For example, when the pressure within the process chamber 104 increases, the pressure transducer 102 measures the pressure and supplies a signal representative of the pressure to the controller 116, which then controls the valve 114 to increase the flow rate from the process chamber 104 to the vacuum pump 112. The vacuum pump 112 can have an output to any suitable location based on the nature of the process.

[0024] In the example of FIG. 1, the pressure transducer 102 is configured to have a fixed pressure 118, and the input pressure of the fluid received via the fluid input line 106 is compared to the fixed pressure 118 to output a pressure signal. For example, as described in more detail below, the pressure transducer 102 can be provided with a sealable exhaust port that can be sealed when a desired pressure is supplied within the pressure transducer 102, and / or the pressure transducer 102 can be assembled and sealed with a volume having a desired reference pressure. The fixed pressure 118 can be a vacuum pressure, or another predetermined fixed reference pressure that is lower than, equal to, or higher than the nominal atmospheric pressure. In the configuration of FIG. 1, the pressure transducer 102 can be used as an absolute pressure sensor.

[0025] FIG. 2 is a schematic diagram of an exemplary pressure transducer 200 that can be used to implement the pressure transducer 102 of FIG. 1. The exemplary pressure transducer 200 includes a first pressure measurement assembly 202, a second pressure measurement assembly 250, and a pressure housing 204. The pressure transducer 200 receives fluid via a fluid input line 208 (e.g., the fluid input line 106 of FIG. 1), measures the absolute pressure of the received fluid, and outputs one or more signals representative of the measured pressure.

[0026] Referring to FIG. 2, the first pressure measurement assembly 202 defines a measurement cavity 222 in combination with the pressure housing 204. The pressure housing 204 is attached to the fluid input line 208 and the first pressure measurement assembly 202 to define the measurement cavity 222. The exemplary pressure housing 204 is fixed and sealed to both the fluid input line 208 and the first pressure measurement assembly 202. The first pressure measurement assembly 202 can also be referred to as the "first sensor core" in that it performs a first measurement that is converted into a first output signal.

[0027] In the illustrated example, the first pressure measurement assembly 202 includes a microelectromechanical pressure sensor 206 coupled to a diaphragm 210. In some examples, the microelectromechanical pressure sensor 206 is a resonant pressure sensor formed by trench etching or an in-plane resonant structure formed by other silicon micromachining, in which the microelectromechanical pressure sensor 206 outputs an output signal having a resonant frequency based on the pressure applied to the diaphragm 210. An exemplary resonant pressure sensor formed by trench etching that can be used to implement the microelectromechanical pressure sensor 206 is described in “Advances in Core Fundamental Sensor Technologies Enabling Improvements in the Metrological Transfer Standards of Pressure Measurement,” Moisoi, et al., Metrologist - NCSLI Worldwide News, Vol. 15, No. 2, pp. 46-55 (2002) (“Moisoi”). The entirety of Moisoi is incorporated herein by reference. FIG. 3 is a perspective view of the exemplary first pressure measurement assembly 202 of FIG. 2. FIG. 4 is another perspective view of the exemplary first pressure measurement assembly 202 of FIG. 2.

[0028] The diaphragm 210 is exposed to the pressure within the measurement cavity 222 and transmits the pressure via an incompressible fluid within the sensor cavity 212 to the microelectromechanical pressure sensor 206. The microelectromechanical pressure sensor 206 is disposed at an end of the sensor cavity 212 remote from the diaphragm 210, with the incompressible fluid filling the remainder of the sensor cavity 212. In some examples, the incompressible fluid is an incompressible oil, which may further be non-conductive. Additionally or alternatively, the microelectromechanical pressure sensor 206 comprises a second diaphragm, such as a silicon diaphragm, that electrically insulates the microelectromechanical pressure sensor 206 from the incompressible fluid while transmitting the force from the fluid to the resonant components of the microelectromechanical pressure sensor 206.

[0029] The sensitivity of the first pressure measurement assembly 202 can be further increased or decreased by increasing or decreasing the diameter of the diaphragm 210.

[0030] The microelectromechanical pressure sensor 206 is coupled to the measurement circuitry 214 via ports 220, 221 for the supply of an input signal and / or an output signal. The first pressure measurement assembly 202 can define a thermal oven chamber 216 in fluid communication with the ambient pressure. The exemplary microelectromechanical pressure sensor 206 can have an integrated pressure reference sealed within the microelectromechanical pressure sensor 206. For example, a silicon diaphragm within the microelectromechanical pressure sensor 206 separates the pressure reference from the sensor cavity 212, and the resonant elements of the microelectromechanical pressure sensor 206 are present within the reference pressure cavity of the microelectromechanical pressure sensor 206. The microelectromechanical pressure sensor 206 measures the pressure applied to the diaphragm 210 with respect to the integrated pressure reference. The integrated pressure reference within the microelectromechanical pressure sensor 206 can be established, for example, during the construction of the microelectromechanical pressure sensor 206.

[0031] An additional port can supply heating power to the heater 218 and / or supply temperature sensor data from the temperature sensor 232 to the control circuit unit 228, enabling control of the heater 218.

[0032] In the example of FIG. 2, the surface of the diaphragm 210 has a circular convolution that may be concentric with the diaphragm 210, which allows for axial deflection of the diaphragm 210 with a minimal change in internal tension and can improve the linearity of the microelectromechanical pressure sensor 206. Since the pressure applied to the diaphragm 210 is measured by the microelectromechanical pressure sensor 206 (e.g., by measuring the change in the resonance frequency of the driven circuit), the accuracy of the microelectromechanical pressure sensor 206 is improved by increasing the linear motion of the diaphragm 210.

[0033] The exemplary microelectromechanical pressure sensor 206 has reduced sensitivity to contamination (e.g., particles from the input line 208) on the diaphragm 210 compared to a conventional capacitance sensor where the diaphragm is part of the capacitance electrode and the sensor output depends on the displacement of the diaphragm. Instead of affecting the capacitance depending on the sensitivity of the diaphragm 210, the diaphragm 210 transmits the pressure in the measurement cavity 222 to the incompressible fluid in the sensor cavity 212. Thus, the life of the microelectromechanical pressure sensor 206 can be extended even in applications where contamination is likely to occur, and the microelectromechanical pressure sensor 206 can be packaged in a smaller package than a conventional sensor by eliminating, for example, a guard volume that reduces contamination on the diaphragm.

[0034] To further expand the measurement operating range beyond the range of the microelectromechanical pressure sensor 206, the exemplary pressure transducer 200 includes a second pressure measurement assembly 250 configured to measure the pressure of the measurement cavity 222 using a different sensor configuration. In the example of FIG. 2, the second pressure measurement assembly 250 is a capacitive diaphragm gauge in which a flexible measurement diaphragm 252 is coupled to a measurement electrode 254. As the pressure in the fluid input line 208 changes relative to a reference pressure (e.g., a vacuum pressure), the measurement diaphragm 252 moves or deflects, changing the capacitance at the measurement electrode 254 by an amount corresponding to the pressure in the fluid input line 208 and / or the pressure within the measurement cavity 222. The capacitance signal is output from the second pressure measurement assembly 250 via one or more signal ports 270.

[0035] In the example of FIG. 2, the second pressure measurement assembly 250 further includes a reference electrode 256 that similarly measures the capacitance as the measurement diaphragm 252 moves in response to pressure. Electrodes 254, 256 are metallized and form two capacitances with the flexible measurement diaphragm 252. The signals generated by both electrodes 254, 256 change with pressure but at different rates. The signal from the reference electrode 256 is output via the signal port 270 and can be used to measure and offset common mode errors (e.g., temperature-induced errors).

[0036] The exemplary second pressure measurement assembly 250 has a sensor housing 258 that includes a reference pressure for the second pressure measurement assembly 250. The sensor housing 258 includes a first section 260 and a second section 262. The first section 260 supports the electrodes 254, 256 and cooperates with a third section 264 to secure the measurement diaphragm 252. For example, the measurement diaphragm 252 can be secured uniformly between the first section 260 and the third section 264 around the perimeter of the outer periphery of the diaphragm 252.

[0037] The measurement diaphragm 252 separates the measurement cavity 222 from a second cavity 272 within the pressure housing 204 in which the electrodes 254, 256 are disposed. The exemplary first pressure measurement assembly 202 is shown as being disposed within the measurement cavity 222 in FIG. 2, although in other examples, the first pressure measurement assembly 202 can be disposed at least partially within the second cavity 272.

[0038] The pressure transducer 200 can include a plasma shield 268 or other guard disposed between the fluid input line 208 and the measurement diaphragm 252. The plasma shield 268 has one or more openings that allow the pressure of the input fluid to be applied to the measurement diaphragm 252, but has one or more surfaces that block contaminants, thereby reducing the accumulation of contaminants on the measurement diaphragm 252.

[0039] The second section 262 is fixed to the end of the first section 260 and surrounds the second pressure measurement assembly 250. The signal port 270 extends through the second section 262 and is hermetically sealed to the second section 262 to maintain the reference pressure within the second pressure measurement assembly 250. The signal port 270 transmits one or more measurement signals (e.g., signals representing the measured pressure) and zero or more reference signals (e.g., signals representing the measured reference signals such as reducing or removing common mode errors present in one or more of the measurement signals). The measurement circuitry 214 is coupled to the signal port 270 and receives the measurement signals and / or reference signals and processes the measurement signals and / or reference signals to obtain a pressure measurement value by the second pressure measurement assembly 250.

[0040] The first pressure measurement assembly 202, the second pressure measurement assembly 250, and / or the pressure housing 204 are at least partially surrounded by one or more outer housings 266. The outer housing 266 can provide thermal insulation and / or physical protection to the first pressure measurement assembly 202 and the second pressure measurement assembly 250.

[0041] The pressure transducer 200 further includes one or more heaters 218 to raise the temperature of the first pressure measurement assembly 202 and / or the temperature of the second pressure measurement assembly 250 (e.g., to reduce the effects caused by the thermal gradient between the microelectromechanical pressure sensor 206 and the process fluid(s)). Exemplary heaters 218 can be disposed at the outer periphery of the outer housing 266 and / or within the outer housing 266, and at the outer periphery of the pressure housing 204, the first pressure measurement assembly 202, and / or the second pressure measurement assembly 250. In some examples, the heater(s) 218 is controlled to heat the first pressure measurement assembly 202 and / or the second pressure measurement assembly 250 to a set temperature that is at least the expected process temperature of the fluid received via the fluid input line 208 in some cases. In some examples, one or more heat spreaders are disposed in contact between the heater(s) 218 and the outer housing 266 and / or between the heater(s) 218 and the pressure housing 204, the first pressure measurement assembly 202, and / or the second pressure measurement assembly 250 to more effectively distribute heat over a wider area and reduce the thermal gradient. The outer housing 266 and / or the pressure housing 204 can be constructed using a heat conductive material to reduce the temperature gradient within the outer housing 266 and / or the pressure housing 204.

[0042] The heater 218 can improve the measurement accuracy by the first pressure measurement assembly 202 and / or the second pressure measurement assembly 250, and / or the measurement stability over the life of the first pressure measurement assembly 202 and / or the second pressure measurement assembly 250 over a wide range of input pressures. The heater(s) 218 can protect against longer-term errors due to process-induced shift. In FIG. 2, two exemplary heaters 218 are shown heating two different zones, but the pressure transducer 200 can comprise more or fewer heaters 218 and / or more or fewer heating zones.

[0043] The pressure transducer 200 further comprises a control circuit unit 228, which receives the measured value from the measurement circuit unit 214, controls the heater power supply 230 to supply power to the heater 218, and receives a temperature feedback signal from the temperature sensor 232 on the heater 218 and / or the pressure housing 204.

[0044] The control circuit unit 228 can be implemented using at least one controller or processor that controls the operation of the pressure transducer 200. The control circuit unit 228 receives and processes multiple inputs. The control circuit unit 228 can comprise one or more microprocessors, such as one or more "general-purpose" microprocessors, one or more dedicated microprocessors and / or ASICs, and / or any other type of processing device. For example, the control circuit unit 228 can comprise one or more digital signal processors (DSPs). The control circuit unit 228 can further comprise a memory device or data storage device.

[0045] The exemplary measurement circuit unit 214 is connected to the output port 220 and the signal port 270 to receive measurement signal(s), and / or is connected to the input port 222 to supply an input or drive signal for driving the resonance of the microelectromechanical pressure sensor 206. For example, the measurement circuit unit 214 applies a drive signal to the microelectromechanical pressure sensor 206 via the input port 222, and measures the frequency of the result signal output by the microelectromechanical pressure sensor 206 via the output port 220 and / or output by the measurement electrode 254 via the signal port 270, and can determine the pressure measured based on the received measurement signal(s). For example, the measurement circuit unit 214 can be calibrated for the combination of frequency and pressure after construction.

[0046] In some examples, the first pressure measurement assembly (e.g., the microelectromechanical pressure sensor 206) outputs a pressure measurement signal with an error less than the threshold value for a fluid having a pressure in a pressure range of at least 1 torr (about 1.3x10 2 Pa) to 100 torr (about 1.3x10 4 Pa) (e.g., a pressure range that may include at least 1 torr (about 1.3x10 2 Pa) to 100 torr (about 1.3x10 4 Pa) and may include pressures less than 1 torr (about 1.3x10 2 Pa) and / or greater than 100 torr (about 1.3x10 4 Pa)). In some examples, the microelectromechanical pressure sensor 206 is configured to output a pressure measurement signal with an error less than the threshold value for a fluid having a pressure of at least 10 torr (about 1.3x10 3 Pa) to 1000 torr (about 1.3x10 5 Pa). In some examples, the microelectromechanical pressure sensor 206 is at least 1 torr (about 1.3x10 2 Pa) to 1000 torr (about 1.3x10 5It is configured to output a pressure measurement signal with an error less than the threshold value for a fluid having the pressure of (Pa). An exemplary threshold error is 0.1500% of the output signal (reading). In other examples, the pressure transducer 200 can be configured to use other pressure ranges as an operating range that includes a two-digit range or a three-digit range (on a Torr scale) and / or a larger operating range while maintaining an error less than the threshold value over the operating range.

[0047] In some examples, the second pressure measurement assembly 250 (e.g., a capacitance diaphragm gauge) is configured to output a pressure measurement signal with an error less than the threshold value for a fluid having a pressure in a pressure range that includes at least 0.01 Torr (about 1.3 Pa) to 1 Torr (about 1.3x10 2 Pa) (e.g., at least 0.01 Torr (about 1.3 Pa) to 1 Torr (about 1.3x10 2 Pa), and may include pressures less than 0.01 Torr (about 1.3 Pa) and / or pressures greater than 1 Torr (about 1.3x10 2 Pa)). In some examples, the second pressure measurement assembly 250 is configured to output a pressure measurement signal with an error less than the threshold value for a fluid having a pressure of at least 0.1 Torr (about 1.3x10 Pa) to 10 Torr (about 1.3x10 3 Pa). In some examples, the second pressure measurement assembly 250 is configured to output a pressure measurement signal with an error less than the threshold value for a fluid having a pressure of at least 0.01 Torr (about 1.3 Pa) to 10 Torr (about 1.3x10 3 Pa). Exemplary threshold errors include 0.1500% and 0.2500%, and may be different from the threshold error of the first pressure measurement assembly 202.

[0048] The first pressure measurement assembly 202 and the second pressure measurement assembly 250 are combined to provide a pressure transducer having a wide operating pressure range that can be measured with low error and high stability. For example, the first pressure measurement assembly 202 and the second pressure measurement assembly 250 can be combined to output a pressure measurement signal with an error less than a threshold value for a fluid having a pressure of at least 0.01 Torr (about 1.3 Pa) to 100 Torr (about 1.3x10 4 Pa), at which pressure the measurement signals from each of the first pressure measurement assembly 202 and the second pressure measurement assembly 250 are used for different sub-ranges of the overall range, and the sub-ranges may partially overlap. In some examples, the first pressure measurement assembly 202 and the second pressure measurement assembly 250 are combined to output a pressure measurement signal with an error less than a threshold value for a fluid having a pressure of at least 0.1 Torr (about 1.3x10 Pa) to 1000 Torr (about 1.3x10 5 Pa). In some examples, the first pressure measurement assembly 202 and the second pressure measurement assembly 250 are combined to output a pressure measurement signal with an error less than a threshold value for a fluid having a pressure of at least 0.01 Torr (about 1.3 Pa) to 1000 Torr (about 1.3x10 5 Pa). In some examples, a certain sub-range of the full output pressure range may have a smaller error than other sub-ranges of the full output pressure range.

[0049] The control circuit unit 228 determines which of the plurality of measurement signals to use as the measured output signal. In the example of FIG. 2, when the pressure is within the first range, the control circuit unit 228 determines the pressure of the input fluid based on the measurement signal from the first pressure measurement assembly 202 (e.g., the microelectromechanical pressure sensor 206), and when the pressure is within the second range, it determines the pressure of the input fluid based on the measurement signal from the second pressure measurement assembly 250 (e.g., the capacitance diaphragm gauge). In some examples, the first range and the second range are selected based on the respective measurement accuracies of the first pressure measurement assembly 202 and the second pressure measurement assembly 250. For example, for a pressure range in which the first pressure measurement assembly 202 results in a measurement error less than a first threshold measurement error, the control circuit unit 228 determines the measured value based on the output signal from the first pressure measurement assembly 202, and for a pressure range in which the second pressure measurement assembly 250 results in a measurement error less than a second threshold measurement error, it determines the measured value based on the output signal from the second pressure measurement assembly 250. The first threshold measurement error and the second threshold measurement error may be the same or different. Since the first range and the second range in FIG. 2 partially overlap, the control circuit unit 228 can select either the first pressure measurement assembly or the second pressure measurement assembly 250 within the overlapping portion of the pressure ranges.

[0050] In some examples, when the error has less impact on the first pressure measurement assembly 202 than on the second pressure measurement assembly 250, the control circuit unit 228 uses the output signal of the first pressure measurement assembly 202 to calibrate the output of the second pressure measurement assembly 250. For example, when the control circuit unit 228 detects that the input pressure is within a predetermined overlap range, the control circuit unit 228 can execute a calibration procedure to calibrate the output signal of the second pressure measurement assembly 250 using the output signal of the first pressure measurement assembly 202. Additionally or alternatively, when the input fluid pressure is within a portion of the overlap range where the second pressure measurement assembly 250 has less error impact than the first pressure measurement assembly 202, the control circuit unit 228 can use the output signal of the second pressure measurement assembly 250 to calibrate the output of the first pressure measurement assembly 202.

[0051] The exemplary pressure transducer 200 can further include a communication circuit unit 234 that communicates the measured value to an external computing device or control device (e.g., the controller 116 of FIG. 1). For example, the communication circuit unit 234 can include any wired and / or wireless communication circuit unit. In some examples, the communication circuit unit 234 performs digital communication that transmits the digital measurement value output by the measurement circuit unit 214. By using digital communication such as EtherCAT, the precise measurement values created using the pressure transducer 200 are maintained during communication. Further, the communication circuit unit 234 can receive a command signal supplied to the control circuit unit 228. The exemplary command signal includes configuration information, such as a target heating temperature, a temperature reporting interval, and / or any other desired configuration information.

[0052] FIG. 5 is a flowchart depicting exemplary machine-readable instructions 500 that the pressure transducer 200 of FIG. 2 can execute to determine the pressure of a fluid.

[0053] In block 502, the pressure transducer 200 receives input fluid into the measurement cavity 222 via the fluid input line 208. For example, the fluid input line 208 can be coupled to the process chamber 104 of FIG. 1 to measure the pressure of the process fluid occurring within the process chamber 104.

[0054] In block 504, the first pressure measurement assembly 202 generates a first pressure measurement signal of the pressure within the measurement cavity 222. For example, the microelectromechanical pressure sensor 206 outputs a signal having a resonance frequency based on the pressure applied to the diaphragm 210 (e.g., via the output port 220). The first pressure measurement assembly 202 outputs the first pressure measurement signal to the measurement circuitry 214.

[0055] In block 506, the second pressure measurement assembly 250 generates a second pressure measurement signal of the pressure within the measurement cavity 222. For example, the electrodes 254, 256 output a measurement signal and a reference signal (e.g., via the signal port 270), and the measurement circuitry 214 can process these to remove the common mode error from the measurement signal. The second pressure measurement assembly 250 outputs the second pressure measurement signal to the measurement circuitry 214.

[0056] In block 508, the control circuitry 228 determines whether the measured pressure (e.g., the first pressure measurement signal and / or the second pressure measurement signal) is within a first pressure range. For example, the first pressure range can be a predetermined pressure range in which the first pressure measurement signal is less than a threshold error. If the measured pressure is within the first range (block 508), in block 510, the control circuitry 228 determines the pressure of the fluid based on the first pressure measurement signal.

[0057] In block 512, the control circuit unit 228 determines whether the measured pressure (e.g., the first pressure measurement signal and / or the second pressure measurement signal) is within the overlapping range between the first pressure range and the second pressure range (e.g., a predetermined pressure range in which the second pressure measurement signal is less than the threshold error). When the measured pressure is within the overlapping range (block 512), in block 514, the control circuit unit 228 calibrates the second pressure measurement assembly 250 using the measurement signal from the first pressure measurement assembly 202. For example, the control circuit unit 228 can adjust the process variable, taught point, and / or other calibration factors for the measurement circuit unit 214 to process the output signal from the second pressure measurement assembly 250 and match it with or based on the corresponding measurement signal from the first pressure measurement assembly 202. In some examples, the control circuit unit 228 limits the calibration to less than a threshold frequency to limit power consumption.

[0058] When the measured pressure is not within the first range (block 508), in block 516, the control circuit unit 228 determines the pressure of the fluid in the measurement cavity 222 based on the second pressure measurement signal from the second pressure measurement assembly 250.

[0059] After calibrating the second pressure measurement assembly 250 (block 514), when the measured pressure is not within the overlapping range (block 512), or after determining the pressure of the fluid in the measurement cavity 222 based on the second pressure measurement signal (block 516), the control returns to block 502 to continue monitoring the pressure.

[0060] The present device and / or method can be implemented in hardware, software, or a combination of hardware and software. The present method and / or system can be implemented in a centralized manner in at least one computing system, processor, and / or other logic circuits, or in a distributed manner where different elements are spread across multiple interconnected computing systems, processors, and / or other logic circuits. Any type of computing system or other device adapted to execute the methods described herein is also suitable. A typical combination of hardware and software may be a processing system integrated into a welding power source that includes a program or other code for controlling the welding power source to execute the methods described herein when loaded and executed. Another typical embodiment may include application-specific integrated circuits or chips such as field programmable gate arrays (FPGAs), programmable logic devices (PLDs), or complex programmable logic devices (CPLDs), and / or system-on-chip (SoC). Some embodiments can include non-transitory machine-readable (e.g., computer-readable) media (e.g., flash memory, optical disks, magnetic storage disks, etc.), such non-transitory machine-readable media storing one or more lines of machine-executable code, thereby causing a machine to perform a process as described herein. As used herein, the term "non-transitory machine-readable media" includes all types of machine-readable storage media and is defined to exclude propagated signals.

[0061] As used herein, "and / or" means any one or more of the items in the list connected by "and / or". As an example, "x and / or y" means any of the three elements of the set {(x), (y), (x,y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" means any of the seven elements of the set {(x), (y), (z), (x,y), (x,z), (y,z), (x,y,z)}. In other words, "x, y and / or z" means "one or more of x, y and z". As used herein, the term "exemplary" serves as a non-limiting example, instance or illustration. As used herein, the term "for example" begins a list of one or more non-limiting examples, instances or illustrations.

[0062] Although the method and / or system has been described with reference to certain embodiments, those skilled in the art will understand that various changes can be made and equivalents can be substituted without departing from the scope of the method and / or system. For example, the blocks and / or components of the disclosed examples can be combined, divided, rearranged, and / or otherwise changed. In addition, many modifications can be made to adapt the teachings of this disclosure to specific situations or materials without departing from the scope of this disclosure. Accordingly, the method and / or system is not limited to the specific embodiments disclosed. Instead, the method and / or system includes all embodiments that fall within the scope of the appended claims, literally or under the doctrine of equivalents.

Claims

1. 1. A pressure transducer comprising: a pressure housing having a first cavity; a fluid input line configured to supply a fluid to the first cavity; a first pressure measurement assembly of a first type configured to output a first measurement signal based on a pressure of the fluid in the first cavity; a second pressure measurement assembly of a second type configured to output a second measurement signal based on the pressure of the fluid in the first cavity; a controller configured to determine the pressure of the fluid in the first cavity based on the first measurement signal when the pressure is within a first range and to determine the pressure of the fluid in the first cavity based on the second measurement signal when the pressure is within a second range; A pressure transducer comprising:

2. The pressure transducer of claim 1 , wherein the first pressure measurement assembly includes a microelectromechanical pressure sensor.

3. 3. The pressure transducer of claim 2, wherein the microelectromechanical pressure sensor comprises a resonating pressure sensor formed by trench etching.

4. The pressure transducer of claim 1 , wherein the second pressure sensor comprises a capacitance diaphragm gauge.

5. 5. The pressure transducer of claim 4, wherein the pressure housing includes a second cavity separated from the first cavity by a measuring diaphragm, and the second pressure measuring assembly is disposed within the second cavity.

6. 6. The pressure transducer of claim 5, further comprising a heater configured to heat at least the first cavity and the second cavity based on a target temperature.

7. The pressure transducer of claim 5 , wherein the first pressure measurement assembly is at least partially disposed within the first cavity or at least partially disposed within the second cavity.

8. The first range and the second range are at least 0.01 Torr (about 1.3 Pa) to 100 Torr (about 1.3×10 ４ 2. The pressure transducer of claim 1 , comprising:

9. The first range and the second range are at least 0.1 Torr (about 1.3×10 Pa) to 1000 Torr (about 1.3×10 ５ 2. The pressure transducer of claim 1 , comprising:

10. The first range and the second range are at least 0.01 Torr (about 1.3 Pa) to 1000 Torr (about 1.3×10 ５ 2. The pressure transducer of claim 1 , comprising:

11. 2. The pressure transducer of claim 1, wherein the controller is configured to calibrate one of the first pressure measurement assembly or the second pressure measurement assembly based on an output of the other of the first pressure measurement assembly or the second pressure measurement assembly when the pressure of the fluid is within a predetermined range.

12. 12. The pressure transducer of claim 11, wherein the first range overlaps the second range, and the predetermined range is at least partially within the overlapping portion of the first range and the second range.

13. The pressure transducer of claim 1 , wherein the first range overlaps with the second range.

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