WO2024103047A1 - Transducteurs de pression comportant une résistance améliorée à une erreur de température - Google Patents

Transducteurs de pression comportant une résistance améliorée à une erreur de température Download PDF

Info

Publication number
WO2024103047A1
WO2024103047A1 PCT/US2023/079444 US2023079444W WO2024103047A1 WO 2024103047 A1 WO2024103047 A1 WO 2024103047A1 US 2023079444 W US2023079444 W US 2023079444W WO 2024103047 A1 WO2024103047 A1 WO 2024103047A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
electrode
pressure sensor
diaphragm
electrode extension
Prior art date
Application number
PCT/US2023/079444
Other languages
English (en)
Inventor
Hai Mei
Ethan EARNEST
Original Assignee
Illinois Tool Works Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US18/506,683 external-priority patent/US20240159611A1/en
Application filed by Illinois Tool Works Inc. filed Critical Illinois Tool Works Inc.
Publication of WO2024103047A1 publication Critical patent/WO2024103047A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/04—Means for compensating for effects of changes of temperature, i.e. other than electric compensation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0072—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance

Definitions

  • This disclosure is directed generally to pressure transducers and, more particularly, to pressure transducers having improved resistance to temperature error.
  • Pressure sensors or pressure transducers, measure the pressure of a fluid input to the sensor compared to a reference pressure.
  • Pressure sensors may be constructed to compare the input pressure to a fixed reference pressure or to a variable reference pressure.
  • FIG. 1 A is a block diagram of an example process control system including a pressure transducer having a fixed reference pressure, in accordance with aspects of this disclosure.
  • FIG. IB is a block diagram of an example process control system including a pressure transducer coupled to a variable source of reference pressure, in accordance with aspects of this disclosure.
  • FIG. 2 is a schematic diagram of an example pressure sensor which may be used to implement the pressure sensors of FIGS. 1A and/or IB, in accordance with aspects of this disclosure.
  • FIG. 3 is an exploded perspective view of the example pressure measurement assembly of FIG. 2.
  • FIG. 4 is another exploded perspective view of the example pressure measurement assembly of FIG. 2.
  • FIG. 5 is a flow-chart representative of an example method which may be performed to assemble the example pressure sensor of FIG. 2.
  • Conventional pressure sensors convert input pressures to pressure signals.
  • Some conventional sensors detect pressure differences between an input pressure and a reference pressure based on a capacitance between a flexible diaphragm and a fixed electrode.
  • conventional capacitive pressure sensors are sensitive to temperature differences, in that changes in temperature may cause friction betw een contacting components and/or changes in the capacitance present between the diaphragm and the electrode.
  • thermal expansion of the components in conventional pressure sensors may cause a change in the gap between the diaphragm and the electrode, resulting in error in the pressure measurements.
  • some conventional capacitive pressure sensors include multiple electrodes, including a reference electrode to compensate for changes in temperature.
  • a pressure measurement assembly includes a first body that defines a reference pressure cavity in conjunction with the diaphragm, and in which the electrode is present.
  • the geometries and/or the materials of the first body, the electrode, and/or an electrode extension are selected to offset thermal expansion to thereby reduce or eliminate thermally induced error.
  • Disclosed pressure transducers may be less expensive and/or less complex to construct, more reliable, and/or easier to service and/or maintain than conventional capacitive pressure sensors.
  • a getter that is typically used in vacuum pressure manometers may be eliminated by coating the reference pressure cavity’ with a non-outgassing coating, such as Parylene-C.
  • Disclosed example pressure transducers have improved performance compared to conventional capacitive pressure sensors due to improved thermal performance and/or improved signal strength relative to multiple-electrode pressure sensors due to the omission of the reference electrodes and associated subtraction of signals.
  • fluid includes matter in both liquid and gaseous states.
  • Disclosed example pressure sensors include: a first body defining a reference pressure cavity; a second body defining a measured pressure cavity and having an inlet configured to receive a fluid; a diaphragm between the reference pressure cavity and the measured pressure cavity’; a single electrode having a plate portion having a first face facing the diaphragm and separated from the diaphragm by a gap to form a capacitance between the electrode and the diaphragm; an electrode extension fixed to the electrode and extending through an aperture in the first body; an electrically insulative joint disposed between the electrode extension and the first body at least partially within the aperture, in which the first body, the electrode, and the electrode extension have respective geometries and coefficients of thermal expansion selected such that, in response to changes in temperature (e.g., rise in temperature), combined expansion of the electrode and the electrode extension offsets changes in the gap resulting from expansion of the first body.
  • a first body defining a reference pressure cavity
  • a second body defining a measured pressure cavity and having an
  • the electrically insulative joint provides a hermetic seal between the electrode extension and the first body.
  • the seal includes glass.
  • the first body has a higher coefficient of thermal expansion than both the seal and the electrode extension.
  • the seal forms a compression seal between the first body and the electrode extension.
  • the first body includes an evacuation port.
  • the evacuation port is capable of selective sealing to fix a pressure within the reference pressure cavity.
  • Some example pressure sensors further include a getter within the reference pressure cavity, in which the fixed pressure is a vacuum pressure.
  • an internal surface of the first body is coated to reduce outgassing.
  • the evacuation port is configured to be coupled to a source of reference pressure to configure the pressure sensor as a differential pressure sensor.
  • the evacuation port is configured to be vented to an ambient pressure to configure the pressure sensor as a gauge pressure type.
  • the first body includes a corrosion resistant alloy.
  • the electrode extension comprises a Kovar® alloy or alloy 52.
  • the electrode includes metal such as stainless steel having a higher coefficient of thermal expansion than the first body material.
  • Some example pressure sensors further include measurement circuitry coupled to the electrode extension and configured to convert the capacitance between the electrode and the diaphragm to a pressure value.
  • FIG. 1A is a block diagram of an example process control system 100 including a pressure transducer 102.
  • the example process control system 100 of FIG. 1 includes a process chamber 104, to which the pressure transducer 102 is fluidly coupled via a fluid input line 106 to measure the pressure of the process chamber 104.
  • the example process chamber 104 may receive one or more inputs, such as process feed materials, via a corresponding number of feed lines 108a, 108b, which may be controlled via mass flow controllers 110a, 110b.
  • the example system 100 may include a vacuum pump 112, or other pressure control pump, and a valve 114 to control a flow rate between the vacuum pump 112 and the process chamber 104.
  • the valve 114 may be controlled by a controller 116, computing device, and/or any other control technique, to maintain the pressure in the process chamber 104 within a desired range.
  • the example pressure transducer 102 is communicatively coupled to the controller 116 to provide pressure feedback to the controller 116 (e g., for use in a pressure control loop).
  • the pressure transducer 102 measures the pressure and provides 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 may have an output to any appropriate location based on the nature of the process.
  • the pressure transducer 102 is configured with a fixed pressure 118, to which an input pressure of a fluid received via the fluid input line 106 is compared to output a pressure signal.
  • the pressure transducer 102 may be provided with a sealable evacuation port which may be sealed when the desired pressure is provided within the pressure transducer 102, and/or the pressure transducer 102 may be assembled and sealed within a volume having the desired reference pressure.
  • the fixed pressure 118 may be a vacuum pressure or another predetermined fixed reference pressure which may be below, at, or above a nominal atmospheric pressure. In the configuration of FIG. 1A. the pressure transducer 102 may be used as an absolute pressure sensor.
  • FIG. IB is a block diagram of another example process control system 150.
  • the example process control system 150 includes the example pressure transducer 102, the process chamber 104, the fluid input line 106, the feed lines 108a, 108b, the mass flow controllers 110a, 110b, the vacuum pump 112, the valve 114, and the controller 116 of FIG. 1 A.
  • the pressure transducer 102 is coupled to a variable source 152 of reference pressure that is external to the pressure transducer 102.
  • the pressure transducer 102 may have a port (e.g., a selectively sealable evacuation port) that is connected to a source of reference pressure to operate as a pressure sensor with a variable reference, and/or which is vented to an ambient pressure to operate as a pressure gauge.
  • a port e.g., a selectively sealable evacuation port
  • FIG. 2 is a schematic diagram of an example pressure transducer 200 which may be used to implement the pressure transducers 102, 150 of FIGS. 1A and/or IB.
  • the example pressure transducer 200 includes a pressure measurement assembly 202, an inner housing 204, and an outer housing 206.
  • the pressure transducer 200 receives a 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.
  • a fluid input line 208 e.g., the fluid input line 106 of FIG. 1
  • the pressure measurement assembly 202 is attached to the fluid input line 208.
  • the pressure measurement assembly 202 may also be referred to as the ‘"sensor core,” in that the pressure measurement assembly 202 performs the measurements which are converted to output signals.
  • the pressure measurement assembly 202 is at least partially surrounded by the inner housing 204.
  • the inner housing 204 may provide thermal insulation and/or physical protection to the pressure measurement assembly 202.
  • Both the pressure measurement assembly 202 and the inner housing 204 are at least partially surrounded by the outer housing 206.
  • the pressure measurement assembly 202 is a capacitance pressure sensor, in which a flexible diaphragm 210 is separated from an electrode 212 by a gap 214.
  • the pressure measurement assembly 202 includes a first body 216 that defines a reference pressure cavity 218, and a second body 220 that defines a measured pressure cavity 222.
  • the second body 220 is coupled to the fluid input line 208, such that the measured pressure cavity 222 has the same pressure as the fluid in the fluid input line 208.
  • the second body 220 may be welded, brazed, or otherwise sealed against the fluid input line 208 to provide a hermetic seal.
  • the example electrode 212 has a face 224 that faces the diaphragm 210, and which is separated from the diaphragm by a substantially constant gap.
  • the diaphragm 210 and the electrode 212 form a capacitance which changes as the distance between the diaphragm 210 and the electrode 212 changes, and which can be measured to determine the relative pressure between the reference pressure cavity 218 and the measured pressure cavity 222.
  • the electrode 212 is coupled to an electrode extension 226, which extends from the electrode 212 through an aperture 228 in the first body 216 to an exterior of the first body 216.
  • the electrode extension 226 may be integral or attached to the electrode 212.
  • the electrode 212 and the electrode extension 226 may be collectively referred to herein as an electrode assembly.
  • the example pressure measurement assembly 202 further includes a joint 230 positioned between the electrode extension 226 and the first body 216, at least partially within the aperture 228.
  • the joint 230 provides electrical insulation between the electrode extension 226 and the first body 216.
  • the diaphragm 210 is positioned betw een the first and second bodies 216, 220, which are welded or otherwise mechanically and hermetically attached together.
  • the dimensions of the first body 216, the electrode 212, and the electrode extension 226 establishes the gap 214 between the electrode 212 and the diaphragm 210.
  • the joint 230 further provides a hermetic seal.
  • the joint 230 may be implemented using a glass insert, such as S8061-type glass.
  • the materials of the first body 216, the joint 230, and the electrode extension 226 may be selected such that the coefficient of thermal expansion of the first body 216 is larger than the coefficients of thermal expansion of both the joint 230 and the electrode extension 226.
  • the seal provided by the joint 230 may be established by heating the first body 216, the joint 230, and the electrode extension 226, causing the joint 230 to melt.
  • the joint 230 solidifies while the first body 216 and the electrode extension 226 shrink.
  • the larger coefficient of thermal expansion of the first body 216 causes the first body 216 to compress the joint 230 and the electrode extension 226.
  • the example first body 216, the electrode 212, and the electrode extension 226 also have configured geometries and materials such that combined expansion of the electrode 212 and the electrode extension 226 offsets changes in the gap 214 resulting from expansion of the first body 216.
  • the first body 216 expands such that the electrode extension 226 and the electrode 212 are pulled in a direction away from the diaphragm.
  • the electrode 212 and the electrode extension 226 expand as the temperature increases to move the face 224 of the electrode 212 toward the diaphragm.
  • the example first body 216, the electrode 212, and the electrode extension 226 of the example pressure measurement assembly 202 have geometries and materials (e.g., coefficients of thermal expansion) that offset the changes in the gap 214 that would occur due to the expansion of the first body 216 with offsetting expansion by of the electrode extension 226 and the electrode 212.
  • the first body 216 may be constructed to have a particular dimension 232 corresponding to the height of the reference pressure cavity 218. Additionally, the first body 216 is constructed of a material which has a first coefficient of linear thermal expansion (also referred to herein as coefficient of thermal expansion) CLTEbody.
  • the electrode 212 is constructed to have a height dimension 234, and the electrode extension 226 has a partial height dimension 236 between the interface with the electrode 212 and the interior end of the aperture 228 (e.g., where the joint 230 constrains movement of the electrode extension 226).
  • the electrode 212 is constructed with a material having a second coefficient of thermal expansion CLTEeiectrode.
  • the electrode extension 226 is constructed with a material having a third coefficient of thermal expansion CLTEext. Equation 1 below shows the relationship between the dimensions 232-236 and the coefficients of thermal expansion:
  • body height 232 * CLTE body (electrode height 234 * CLTE eiectrode ) + (partial extension height 236 * CLTE ext ) (Equation 1)
  • Example materials that may be used to construct the first body 216 and/or the second body 220 include corrosion resistant alloys, such as nickel alloys (e.g., Inconel® alloy) and/or superalloys, cobalt superalloys, iron superalloys, aluminum, copper alloys, titanium, and/or stainless steel.
  • corrosion resistant alloys such as nickel alloys (e.g., Inconel® alloy) and/or superalloys, cobalt superalloys, iron superalloys, aluminum, copper alloys, titanium, and/or stainless steel.
  • Example materials that may be used to construct the electrode extension 226 include low thermal expansion alloys such as a Kovar® alloy or alloy 52. As used herein, “low thermal expansion” refers to coefficients of thermal expansion up to 6 x 10’ 6 /°F.
  • Example materials that may be used to construct the electrode 212 include stainless steels and/or other metals, which have higher coefficients of expansion than the material used to construct the first body 216.
  • the diaphragm 210 deflects and changes the capacitance responding to the pressure at the fluid input line 208.
  • the capacitance signal is output from the pressure measurement assembly 202 via the electrode extension 226, which is coupled to measurement circuitry 238 that converts the capacitance to a measurement signal and/or outputs the capacitance signal to an external signal conversion device.
  • the measurement circuitry 238 may correct the measurement signal(s).
  • the measurement signal(s), representative of the measured pressure in the pressure measurement assembly 202 may then be transmitted by the measurement circuitry 238 (e.g., to the controller 116 of FIG. 1A or IB, to another control and/or data collection device, etc.) via a communications port 240 (e.g., a connector).
  • the example measurement circuitry 238 and the communications port 240 are mounted within the pressure transducer 200 on one or more circuit boards 250.
  • the example circuit boards 250 in FIG. 2 are positioned in a parallel orientation with reference to the diaphragm 210. In other examples, one or more of the circuit boards 250 are mounted in other orientations, such as perpendicularly to the diaphragm 210, to improve the packaging and/or resilience of the pressure measurement assembly 202.
  • the first body 216 may include an evacuation port 242 (e.g., a pinch tube or pinch-off tube).
  • the evacuation port 242 is in fluid communication with the reference pressure cavity 218.
  • the pressure e.g., vacuum or other set pressure
  • the pressure measurement assembly 202 may be constructed and sealed in a volume in which the desired reference pressure is present, which fixes the desired reference pressure within the reference pressure cavity 218 when the evacuation port 242 is sealed via welding or pinch-off cold welding in a fixed pressure chamber.
  • a getter may be installed within the reference pressure cavity 218 and activated during manufacture, such as when the fixed reference pressure is established but before the reference pressure cavity 218 is sealed.
  • the inner surfaces of the reference cavity 218 e.g., the first body 216 adjacent the reference pressure cavity 218, the electrode 212, and/or the electrode extension 226) are coated with a substance that reduces or prevents outgassing.
  • An example coating that may be used is Parylene-C.
  • the evacuation port 242 may be left open to ambient pressure and/or connected to a variable source of reference pressure.
  • the example pressure measurement assembly 202 further includes a plasma shield 244, which protects the diaphragm 210 from build-up of process byproducts and particulates from the fluid input line 208.
  • the inner housing 204 is attached to the second body 220 (e.g., using glue, welding, pressure fit, etc.).
  • the outer housing 206 is secured to the measurement circuitry 238 and/or to the inner housing 204 (e.g., via fasteners, adhesive, welding, etc.).
  • the second body 220 further includes a guard volume 246 which is recessed from the plasma shield 244 and from the diaphragm 210.
  • the guard volume 246 accumulates depositions of particulates that may be introduced into the measured pressure cavity 222 via the fluid input line 208. By accumulating particulate in the guard volume 246, the deposition of particulate on the diaphragm is reduced and the lifespan of the diaphragm 210 is extended.
  • the evacuation port 242 is sufficiently large as to facilitate the use of masking fixtures for applying the coating (e.g., Parylene-C) after attachment of the inner housing 204 to the second body 220.
  • the evacuation port 242 may be sealed using a plug 248. Following application of the coating, the plug 248 may be inserted into the evacuation port 242 during establishment of the reference pressure, and electron beam welded or otherwise fixed into the evacuation port 242 to seal the reference pressure within the reference pressure cavity 218.
  • FIG. 3 is an exploded perspective view of the example pressure measurement assembly 202 of FIG. 2.
  • FIG. 4 is another exploded perspective view of the example pressure measurement assembly 202 of FIG. 2.
  • FIG. 5 is a flowchart representative of an example method 500 which may be performed to assemble the example pressure transducer 200 of FIG. 2. While an example manufacturing method is described with reference to FIG. 5, other methods may be used, such as methods involving additive manufacturing and/or other techniques that reduce the number of joining operations to be performed.
  • the first body 216, the electrode assembly (e.g.. the electrode 212 and electrode extension 226) and a seal preform (e.g., the joint 230) are assembled.
  • the seal preform (e.g., the joint 230) is melted and at block 506 the seal preform is cooled to form a solid hermetic seal between the first body 216 and the electrode assembly.
  • block 504 and 506 may be omitted where a hermetic seal is not used.
  • the plasma shield 244 and the second body 220 are assembled.
  • the diaphragm 210, the first body 216, and the second body 220 are assembled and secured (e.g., via welding).
  • the reference pressure in the reference pressure cavity 218 is to be a fixed reference pressure (block 512)
  • the desired reference pressure is induced in the reference pressure cavity 218 in the first body 216.
  • the reference pressure may be drawn through the evacuation port 242.
  • the evacuation port 242 is sealed to fix the reference pressure.
  • the inner housing 204 is installed.
  • the pressure measurement assembly 202 may be inserted into the inner housing 204 and the electrode extension 226 extends through the inner housing 204.
  • the electrode assembly (e.g., via the electrode extension 226) is connected to the measurement circuitry 238.
  • the pressure transducer 200 is calibrated for various pressures and/or temperatures.
  • the outer housing 206 is installed.
  • the inner housing 204 and/or the outer housing 206 may be welded, glued, or otherwise attached to the pressure measurement assembly 202 and/or the fluid input line 208.
  • “and/or” means any one or more of the items in the list joined by “and/or”.
  • “x and/or y” means any element of the three-element set ⁇ (x), (y), (x, y) ⁇ .
  • “x and/or y” means “one or both of x and y”.
  • ”x, y, and/or z means any element of the seven-element set ⁇ (x), (y), (z), (x, y), (x, z), (y, z), (x, y, z) ⁇ .
  • “x, y and/or z” means “one or more of x, y and z”.
  • the term “exemplary’” means serving as a non-limiting example, instance, or illustration.
  • the terms “e.g.,” and “for example” set off lists of one or more non-limiting examples, instances, or illustrations.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

Des exemples de capteurs de pression selon l'invention comprennent : un premier corps définissant une cavité de pression de référence ; un second corps définissant une cavité de pression mesurée et comportant une entrée conçue pour recevoir un fluide ; un diaphragme entre la cavité de pression de référence et la cavité de pression mesurée ; une électrode unique comprenant une partie plaque présentant une première face faisant face au diaphragme et séparée du diaphragme par un espace pour former une capacité entre l'électrode et le diaphragme ; une extension d'électrode fixée à l'électrode et s'étendant à travers une ouverture dans le premier corps ; un joint électriquement isolant disposé entre l'extension d'électrode et le premier corps au moins partiellement à l'intérieur de l'ouverture ; le premier corps, l'électrode et l'extension d'électrode présentant des géométries et coefficients de dilatation thermique respectifs sélectionnés de telle sorte que, en réponse à des changements de température, une dilatation combinée de l'électrode et de l'extension d'électrode compense les modifications de l'espace résultant de la dilatation du premier corps.
PCT/US2023/079444 2022-11-11 2023-11-11 Transducteurs de pression comportant une résistance améliorée à une erreur de température WO2024103047A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US202263424712P 2022-11-11 2022-11-11
US63/424,712 2022-11-11
US18/506,683 US20240159611A1 (en) 2022-11-11 2023-11-10 Pressure transducers having improved resistance to temperature error
US18/506,683 2023-11-10

Publications (1)

Publication Number Publication Date
WO2024103047A1 true WO2024103047A1 (fr) 2024-05-16

Family

ID=89190585

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2023/079444 WO2024103047A1 (fr) 2022-11-11 2023-11-11 Transducteurs de pression comportant une résistance améliorée à une erreur de température

Country Status (1)

Country Link
WO (1) WO2024103047A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130055820A1 (en) * 2011-09-01 2013-03-07 Kevin M. Bourbeau Pressure Measuring Instrument
US20160169759A1 (en) * 2013-11-25 2016-06-16 Horiba Stec, Co., Ltd. Capacitive pressure sensor
WO2016115232A2 (fr) * 2015-01-15 2016-07-21 Mks Instruments, Inc. Polymère composite composants sous vide
US20200191673A1 (en) * 2018-10-22 2020-06-18 Guanghua Wu Capacitive Pressure Transducer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130055820A1 (en) * 2011-09-01 2013-03-07 Kevin M. Bourbeau Pressure Measuring Instrument
US20160169759A1 (en) * 2013-11-25 2016-06-16 Horiba Stec, Co., Ltd. Capacitive pressure sensor
WO2016115232A2 (fr) * 2015-01-15 2016-07-21 Mks Instruments, Inc. Polymère composite composants sous vide
US20200191673A1 (en) * 2018-10-22 2020-06-18 Guanghua Wu Capacitive Pressure Transducer

Similar Documents

Publication Publication Date Title
JP3431606B2 (ja) 圧力センサ
US6550337B1 (en) Isolation technique for pressure sensing structure
US10345180B2 (en) Pressure sensor
JP5133484B2 (ja) 容量性圧力センサー
US5442962A (en) Capacitive pressure sensor having a pedestal supported electrode
US7395716B2 (en) Variable capacitance measuring device
US6120033A (en) Process diaphragm seal
US7377174B2 (en) Capillary weld extension with thermal isolation
EP2304404B1 (fr) Système d'isolement amélioré pour la mesure d'une pression de procédé
US20020029639A1 (en) Isolation technique for pressure sensing structure
US8429979B2 (en) Capacitance type pressure sensor
JPH08271365A (ja) 圧力センサ
CN109211458B (zh) 压力传感器组件
CN112689748B (zh) 液压隔膜密封件和具有液压隔膜密封件的压力换能器
US20030209080A1 (en) Pressure sensor assembly
EP0403254A2 (fr) Capteur de pression hermétique
US11754455B2 (en) Pressure measuring device with free-standing carrier
US20240159611A1 (en) Pressure transducers having improved resistance to temperature error
WO2024103047A1 (fr) Transducteurs de pression comportant une résistance améliorée à une erreur de température
CA2238528A1 (fr) Obturateur de processus auto-active pour transmetteur de commande de processus
CN112262303B (zh) 压力测量装置及其生产方法
US12018993B2 (en) Absolute pressure transducers having improved operating temperature ranges
US7240561B2 (en) Process adapter
JPH05196529A (ja) 差圧伝送器

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23822209

Country of ref document: EP

Kind code of ref document: A1