WO1998041833A1 - Transmitter with isolation assembly for pressure sensor - Google Patents

Transmitter with isolation assembly for pressure sensor Download PDF

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Publication number
WO1998041833A1
WO1998041833A1 PCT/US1998/004844 US9804844W WO9841833A1 WO 1998041833 A1 WO1998041833 A1 WO 1998041833A1 US 9804844 W US9804844 W US 9804844W WO 9841833 A1 WO9841833 A1 WO 9841833A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
transmitter
pressure
cavity
isolation
Prior art date
Application number
PCT/US1998/004844
Other languages
French (fr)
Inventor
Fred C. Sittler
Original Assignee
Rosemount 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
Application filed by Rosemount Inc. filed Critical Rosemount Inc.
Priority to GB9921573A priority Critical patent/GB2338066B/en
Priority to CA002283588A priority patent/CA2283588A1/en
Priority to DE19882225T priority patent/DE19882225B4/en
Publication of WO1998041833A1 publication Critical patent/WO1998041833A1/en

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
    • 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
    • G01L19/0007—Fluidic connecting means
    • G01L19/0046—Fluidic connecting means using isolation membranes

Definitions

  • the present invention relates to a pressure transmitter of the type used to monitor pressure of an industrial process. More specifically, the invention relates to an isolation assembly for a pressure sensor in a transmitter.
  • Pressure transmitters use an isolation assembly having an isolation diaphragm which isolates a pressure sensor carried in a pressure sensor coupling .in the transmitter from the process fluid being sensed. Pressure is transferred from the isolation diaphragm to a sensor cavity of the sensor coupling which carries the sensor and a substantially incompressible isolation fluid. The pressure of the isolation fluid reflects the pressure of the process fluid and the pressure sensor responsively provides an output.
  • U.S. Patent No. 4,833,922 entitled “MODULAR PRESSURE TRANSMITTER”, U.S. Patent No. 5,094,109 entitled “PRESSURE TRANSMITTER WITH STRESS ISOLATION DEPRESSION", and U.S. Patent No. 5,524,492 entitled “PRESSURE TRANSMITTER ISOLATION DIAPHRAGM show pressure transmitters of this type.
  • Thermal expansion of components in the transmitter can cause errors in pressure measurements.
  • compression and thermal expansion of the isolation fluid typically an oil
  • thermal expansion of components of the isolation assembly can cause a change in the measured pressure.
  • the pressure invention includes a pressure transmitter for sensing pressure of a process fluid.
  • the transmitter includes a transmitter housing, transmitter circuitry and a pressure sensor coupled to the transmitter circuitry.
  • a sensor coupling in the transmitter housing defines a sensor cavity around the pressure sensor which is filled with a isolation fluid.
  • the sensor coupling has a first thermal expansion coefficient.
  • An isolation diaphragm is coupled to the sensor coupling and seals the sensor cavity from the process fluid.
  • a thermal compensation member couples to the sensor cavity and has a second thermal expansion coefficient which is selected whereby the volume changes in a manner which compensates for pressure changes due to thermal expansion of the sensor coupling and/or the isolation fluid.
  • Various aspects of the invention include reducing the amount of isolation fluid, using a thin isolation diaphragm and compensation for thermal expansion of the isolation fluid and associated mechanical components .
  • Figure 1 is a fragmentary view showing a transmitter including a sensor assembly in accordance with one embodiment of the present invention.
  • Figure 2 is a cross-sectional view of the sensor assembly of Figure 1.
  • Figure 3 is an exploded perspective view of the sensor assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • FIG. 1 shows pressure transmitter 10 having transmitter body 12, flange 13 and pressure sensor assembly 14 in accordance with the present invention.
  • Transmitter body 12 includes sensor circuitry 18 and transmitter circuitry 20.
  • a pressure sensor 16 is carried in assembly 14 and couples to sensor circuitry 18.
  • Pressure sensor 16 is responsive to pressure PI in passageway 28 and flange 13.
  • Sensor circuitry 18 couples to transmitter circuitry 20 through communication bus 22.
  • Transmitter circuitry 20 sends information related to pressure PI of process fluid over a two wire communication circuit 26. For example, this may be a 4-20 A current loop or a process control industry standard HART® or Fieldbus loop.
  • pressure sensor assemblies use an oil as an isolation fluid.
  • the oil is used to fill a cavity which is isolated from process fluid by an isolation diaphragm.
  • the deflection pressurizes the isolation fluid and a pressure sensor in the sensor assembly senses the pressure. This arrangement prevents the corrosive or otherwise damaging process fluid from directly contacting the pressure sensor.
  • the present invention recognizes that typical prior art sensor assemblies contribute errors to pressure measurements.
  • the displacement of the isolation diaphragm requires a force to move the diaphragm, which reduces the pressure transferred to the isolation fluid.
  • the actual pressure of the isolation fluid is less than the actual pressure of the process fluid.
  • the amount of this error can be reduced by designing a diaphragm and sensor such that relatively little movement of the diaphragm occurs over the range of measured pressures.
  • a sensor assembly having a one inch diameter stainless steel isolation diaphragm with a thickness of 1 mil will have a pressure error of 0.0001 psi and have a volume displacement of 1 x 10 "4 cubic in.
  • Such a pressure sensor which may be brazed into the assembly is preferred since it reduces unnecessary volume of oil, as its integral feed through necessitates less oil volume than does a wire-bonded sensor.
  • the error introduced due to compressibility of the oil can be reduced by minimizing the volume of the oil and by making the walls of the assembly which form the cavity for the oil as rigid as possible.
  • one aspect of the present invention addresses error introduced through thermal expansion of components and thermal expansion of the isolation fluid. Specifically, the invention provides a thermal compensation member in the sensor assembly that compensates for dimensional variations due to thermal expansion.
  • FIG. 2 is a cross-sectional view of pressure sensor assembly 14 in accordance with one embodiment.
  • Sensor assembly 14 is coupled to flange 13 of transmitter 10.
  • Sensor assembly 14 includes sensor coupling 42 and low expansion collar 44 which provides a thermal compensation member in accordance with the invention.
  • Isolation diaphragm 46 receives pressure PI for passageway 28 and defines a diaphragm cavity 48 between isolation diaphragm 46 and a substantially flat face of sensor coupling 42.
  • Sensor coupling 42 includes stress isolation regions 50 which are, in one embodiment, regions of reduced thickness in the base of coupling 42 which provide stress isolation.
  • Collar 44 is coupled to sensor coupling 42 at TIG (Tungsten Inert Gas) weld 54 or by other appropriate means.
  • Sensor 16 couples to cap 80 at braise joint 56.
  • Collar 44 couples to cap 80, which comprises a low expansion ceramic, by a braze or other adhesive methods.
  • a collar outer cavity 58 and collar lower cavity 60 are formed between collar 44 and sensor coupling 42.
  • Collar inner cavity 62 is formed between collar 44 and pressure sensor 16.
  • Passageway 64 couples cavities 58, 60 and 62 with cavity 48, forming a sensor cavity 82 filled with an incompressible isolation fluid such as an oil whereby pressure on diaphragm 46 is transferred to pressure sensor 16.
  • Figure 3 is an exploded view of pressure sensor assembly 14. Ceramic-like cap 80 seals pressure sensor 16 (not shown in Figure 3).
  • Cap 80 is bonded to collar 44 which has sensor cavity 82 formed therein and adapted for receiving sensor 16. Collar 44 is received in coupling 42.
  • isolation diaphragm 46 has a 1 inch diameter and cavity 48 is 0.005 inches in depth, so as to provide overpressure protection when filled with oil.
  • Passageway 64 has a diameter of 0.020 inches and is 0.200 inches in length.
  • a cross-section of sensor 16 may be rectangular and there is a gap of 0.008 inches between sensor 16 and collar 44 which forms the collar inner cavity 62.
  • the gap forming cavity 60 is 0.005 inches and the gap forming collar outer cavity 58 is 0.0015 inches.
  • Sensor coupling 42 and collar 44 are cylindrical in shape.
  • Sensor coupling 42 may be of 316 stainless steel and lower expansion collar 44 is a material having a lower coefficient of expansion than of the stainless steel, such as a ceramic, for example cordierite, available from Superior Technical Ceramics of St.
  • the temperature coefficient of expansion for cordierite is 2.1 x 10 "6 in/in°C.
  • the collar outer cavity 58 is formed by an annular gap with a volume which increases with temperature to thereby compensate for volumetric thermal expansion of the fill fluid or other components in assembly 14.
  • the invention includes placement of a thermal compensation member within isolation fluid used to couple a pressure sensor to a pressure to be sensed.
  • the thermal compensation member is selected to expand or contract, as appropriate, at a rate which is selected to compensate for thermal volumetric or spacial variations in components of the sensor assembly isolation fluid or other elements.
  • the total volume of the isolation fluid is reduced and a pressure sensor is used which does not substantially deform under pressure.
  • the invention may be used with any type of pressure sensor for measuring static pressure, gauge pressure, differential pressure, etc., or other parameters related to pressure, such as flow, level, etc, or parameters which are affected by expansion of components.
  • the invention is particularly well suited for implementation in process control instruments such as transmitters in which the process fluid being sensed may be corrosive or contaminated which may lead to damage to the pressure sensor. Further, the particular dimensions, volumes, shapes, etc. are merely for one preferred design and may be modified for accuracy or other design constraints as appropriate .

Abstract

A process control transmitter (10) includes a transmitter housing (12) and transmitter circuitry (20) adapted for providing a transmitter output related to a sensed pressure. A sensor coupling (42) in the housing (12) defines a pressure sensor cavity which is filled with isolation fluid. An isolation diaphragm (46) separates the sensor cavity from a process fluid and is adapted to transmit pressure therebetween. The pressure sensor (16) is mounted in the sensor cavity and provides an output related to pressure to the transmitter circuitry (20). A thermal compensation member (44) is coupled to the sensor cavity and has a thermal expansion coefficient which is different than a thermal expansion coefficient for the sensor coupling (42). The compensation member (44) is adapted to compensate for pressure changes due to thermal expansion of the components or isolation fluid.

Description

TRANSMITTER WITH ISOLATION ASSEMBLY FOR PRESSURE SENSOR
BACKGROUND OF THE INVENTION
The present invention relates to a pressure transmitter of the type used to monitor pressure of an industrial process. More specifically, the invention relates to an isolation assembly for a pressure sensor in a transmitter.
Pressure transmitters use an isolation assembly having an isolation diaphragm which isolates a pressure sensor carried in a pressure sensor coupling .in the transmitter from the process fluid being sensed. Pressure is transferred from the isolation diaphragm to a sensor cavity of the sensor coupling which carries the sensor and a substantially incompressible isolation fluid. The pressure of the isolation fluid reflects the pressure of the process fluid and the pressure sensor responsively provides an output. U.S. Patent No. 4,833,922 entitled "MODULAR PRESSURE TRANSMITTER", U.S. Patent No. 5,094,109 entitled "PRESSURE TRANSMITTER WITH STRESS ISOLATION DEPRESSION", and U.S. Patent No. 5,524,492 entitled "PRESSURE TRANSMITTER ISOLATION DIAPHRAGM show pressure transmitters of this type.
Thermal expansion of components in the transmitter can cause errors in pressure measurements. For example, compression and thermal expansion of the isolation fluid, typically an oil, can introduce errors in pressure measurement. Additionally, thermal expansion of components of the isolation assembly can cause a change in the measured pressure. SUMMARY OF THE INVENTION
The pressure invention includes a pressure transmitter for sensing pressure of a process fluid.
The transmitter includes a transmitter housing, transmitter circuitry and a pressure sensor coupled to the transmitter circuitry. A sensor coupling in the transmitter housing defines a sensor cavity around the pressure sensor which is filled with a isolation fluid.
The sensor coupling has a first thermal expansion coefficient. An isolation diaphragm is coupled to the sensor coupling and seals the sensor cavity from the process fluid. A thermal compensation member couples to the sensor cavity and has a second thermal expansion coefficient which is selected whereby the volume changes in a manner which compensates for pressure changes due to thermal expansion of the sensor coupling and/or the isolation fluid. Various aspects of the invention include reducing the amount of isolation fluid, using a thin isolation diaphragm and compensation for thermal expansion of the isolation fluid and associated mechanical components .
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a fragmentary view showing a transmitter including a sensor assembly in accordance with one embodiment of the present invention.
Figure 2 is a cross-sectional view of the sensor assembly of Figure 1.
Figure 3 is an exploded perspective view of the sensor assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 shows pressure transmitter 10 having transmitter body 12, flange 13 and pressure sensor assembly 14 in accordance with the present invention. Transmitter body 12 includes sensor circuitry 18 and transmitter circuitry 20. A pressure sensor 16 is carried in assembly 14 and couples to sensor circuitry 18. Pressure sensor 16 is responsive to pressure PI in passageway 28 and flange 13. Sensor circuitry 18 couples to transmitter circuitry 20 through communication bus 22. Transmitter circuitry 20 sends information related to pressure PI of process fluid over a two wire communication circuit 26. For example, this may be a 4-20 A current loop or a process control industry standard HART® or Fieldbus loop. Transmitter
10 is wholly powered over circuit 26 from control room
27 having a voltage source 29 and resistor 31 in series.
Typically, pressure sensor assemblies use an oil as an isolation fluid. The oil is used to fill a cavity which is isolated from process fluid by an isolation diaphragm. As the diaphragm is deflected due to pressure from the process fluid, the deflection pressurizes the isolation fluid and a pressure sensor in the sensor assembly senses the pressure. This arrangement prevents the corrosive or otherwise damaging process fluid from directly contacting the pressure sensor.
The present invention recognizes that typical prior art sensor assemblies contribute errors to pressure measurements. First, the displacement of the isolation diaphragm requires a force to move the diaphragm, which reduces the pressure transferred to the isolation fluid. As a result, the actual pressure of the isolation fluid is less than the actual pressure of the process fluid. The amount of this error can be reduced by designing a diaphragm and sensor such that relatively little movement of the diaphragm occurs over the range of measured pressures. Second, it is desirable to use an isolation diaphragm which introduces a pressure error due to diaphragm displacement which is less than the maximum sensitivity of the pressure sensor. For example, a sensor assembly having a one inch diameter stainless steel isolation diaphragm with a thickness of 1 mil will have a pressure error of 0.0001 psi and have a volume displacement of 1 x 10"4 cubic in. Such a pressure sensor which may be brazed into the assembly is preferred since it reduces unnecessary volume of oil, as its integral feed through necessitates less oil volume than does a wire-bonded sensor.
Next, the error introduced due to compressibility of the oil can be reduced by minimizing the volume of the oil and by making the walls of the assembly which form the cavity for the oil as rigid as possible. Finally, one aspect of the present invention addresses error introduced through thermal expansion of components and thermal expansion of the isolation fluid. Specifically, the invention provides a thermal compensation member in the sensor assembly that compensates for dimensional variations due to thermal expansion.
Figure 2 is a cross-sectional view of pressure sensor assembly 14 in accordance with one embodiment. Sensor assembly 14 is coupled to flange 13 of transmitter 10. Sensor assembly 14 includes sensor coupling 42 and low expansion collar 44 which provides a thermal compensation member in accordance with the invention. Isolation diaphragm 46 receives pressure PI for passageway 28 and defines a diaphragm cavity 48 between isolation diaphragm 46 and a substantially flat face of sensor coupling 42. Sensor coupling 42 includes stress isolation regions 50 which are, in one embodiment, regions of reduced thickness in the base of coupling 42 which provide stress isolation. Collar 44 is coupled to sensor coupling 42 at TIG (Tungsten Inert Gas) weld 54 or by other appropriate means. Sensor 16 couples to cap 80 at braise joint 56. Collar 44 couples to cap 80, which comprises a low expansion ceramic, by a braze or other adhesive methods. A collar outer cavity 58 and collar lower cavity 60 are formed between collar 44 and sensor coupling 42. Collar inner cavity 62 is formed between collar 44 and pressure sensor 16. Passageway 64 couples cavities 58, 60 and 62 with cavity 48, forming a sensor cavity 82 filled with an incompressible isolation fluid such as an oil whereby pressure on diaphragm 46 is transferred to pressure sensor 16. Figure 3 is an exploded view of pressure sensor assembly 14. Ceramic-like cap 80 seals pressure sensor 16 (not shown in Figure 3). Cap 80 is bonded to collar 44 which has sensor cavity 82 formed therein and adapted for receiving sensor 16. Collar 44 is received in coupling 42.
In one example embodiment, isolation diaphragm 46 has a 1 inch diameter and cavity 48 is 0.005 inches in depth, so as to provide overpressure protection when filled with oil. Passageway 64 has a diameter of 0.020 inches and is 0.200 inches in length. A cross-section of sensor 16 may be rectangular and there is a gap of 0.008 inches between sensor 16 and collar 44 which forms the collar inner cavity 62. The gap forming cavity 60 is 0.005 inches and the gap forming collar outer cavity 58 is 0.0015 inches. Sensor coupling 42 and collar 44 are cylindrical in shape. Sensor coupling 42 may be of 316 stainless steel and lower expansion collar 44 is a material having a lower coefficient of expansion than of the stainless steel, such as a ceramic, for example cordierite, available from Superior Technical Ceramics of St. Albans, Vermont or Coors Ceramics Company of Golden, Colorado. The temperature coefficient of expansion for cordierite is 2.1 x 10"6 in/in°C. The collar outer cavity 58 is formed by an annular gap with a volume which increases with temperature to thereby compensate for volumetric thermal expansion of the fill fluid or other components in assembly 14.
Analysis of this design shows that the volumetric change of the cavity and fluid system over a temperature range of -4°C to 52°C is 2.23 x 10"5 cu. in. Thus, the pressure stays relatively constant over pressure because the sensor coupling expands at a greater rate than the cordierite thereby causing gap 58 to expand and compensate for expansion of the oil fill fluid.
The particular embodiments set forth herein are simply the preferred embodiments and a wide variation is considered to be within the scope of the present invention. The invention includes placement of a thermal compensation member within isolation fluid used to couple a pressure sensor to a pressure to be sensed. The thermal compensation member is selected to expand or contract, as appropriate, at a rate which is selected to compensate for thermal volumetric or spacial variations in components of the sensor assembly isolation fluid or other elements. In one preferred embodiment, the total volume of the isolation fluid is reduced and a pressure sensor is used which does not substantially deform under pressure. The invention may be used with any type of pressure sensor for measuring static pressure, gauge pressure, differential pressure, etc., or other parameters related to pressure, such as flow, level, etc, or parameters which are affected by expansion of components. The invention is particularly well suited for implementation in process control instruments such as transmitters in which the process fluid being sensed may be corrosive or contaminated which may lead to damage to the pressure sensor. Further, the particular dimensions, volumes, shapes, etc. are merely for one preferred design and may be modified for accuracy or other design constraints as appropriate . Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:
1. A transmitter for providing an output indicative of a pressure of a process fluid, comprising: a transmitter housing; transmitter circuitry in the transmitter housing for providing the output in response to a sensor output; a sensor coupling coupled to the transmitter housing defining a sensor cavity having a cavity volume filled with isolation fluid, the sensor coupling having, a first thermal expansion coefficient; an isolation diaphragm coupled to the sensor coupling and defining the sensor body therein, the isolation diaphragm adapted to couple the pressure to the isolation fluid; a pressure sensor mounted in the sensor cavity and coupled to the isolation fluid, the pressure sensor providing the sensor output to the transmitter circuitry; and a thermal compensation member coupled to the cavity having a second thermal expansion coefficient to compensate for changes in the cavity volume due to thermal expansion of the sensor coupling.
2. The transmitter of claim 1 wherein the thermal compensation member is carried within the sensor cavity defined by the sensor coupling.
3. The transmitter of claim 1 wherein the thermal compensation member includes a cavity and the pressure sensor is carried within the cavity.
4. The transmitter of claim 1 wherein the thermal compensation member includes cordierite.
5. The transmitter of claim 1 wherein the second thermal expansion coefficient is less than the first thermal expansion coefficient.
6. The transmitter of claim 1 wherein the thermal compensation member fits within the sensor coupling and the cavity volume includes a outer cavity formed between the sensor coupling and the thermal compensation member.
7. The transmitter of claim 1 wherein the pressure sensor is carried within the thermal compensation member and the cavity volume includes an inner cavity defined between the thermal compensation member and the pressure sensor.
8. The transmitter of claim 1 wherein the transmitter circuitry output comprises a 4-20 mA signal.
9. The transmitter of claim 1 wherein the output comprises a digital signal.
10. The transmitter if claim 1 wherein the pressure sensor comprises sapphire.
11. The transmitter of claim 1 wherein the sensor comprises an elongated element coupled at one end to the sensor coupling.
12. The transmitter of claim 1 wherein the sensor coupling includes a region of reduced thickness to provide stress isolation to the pressure sensor.
PCT/US1998/004844 1997-03-14 1998-03-06 Transmitter with isolation assembly for pressure sensor WO1998041833A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB9921573A GB2338066B (en) 1997-03-14 1998-03-06 Transmitter with isolation assembly for pressure sensor
CA002283588A CA2283588A1 (en) 1997-03-14 1998-03-06 Transmitter with isolation assembly for pressure sensor
DE19882225T DE19882225B4 (en) 1997-03-14 1998-03-06 Transmitter with separation unit for pressure sensor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/818,379 US5731522A (en) 1997-03-14 1997-03-14 Transmitter with isolation assembly for pressure sensor
US08/818,379 1997-03-14

Publications (1)

Publication Number Publication Date
WO1998041833A1 true WO1998041833A1 (en) 1998-09-24

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US (1) US5731522A (en)
CN (1) CN1134654C (en)
CA (1) CA2283588A1 (en)
DE (1) DE19882225B4 (en)
GB (1) GB2338066B (en)
WO (1) WO1998041833A1 (en)

Families Citing this family (64)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6484585B1 (en) 1995-02-28 2002-11-26 Rosemount Inc. Pressure sensor for a pressure transmitter
US7623932B2 (en) * 1996-03-28 2009-11-24 Fisher-Rosemount Systems, Inc. Rule set for root cause diagnostics
US8290721B2 (en) 1996-03-28 2012-10-16 Rosemount Inc. Flow measurement diagnostics
US6578435B2 (en) 1999-11-23 2003-06-17 Nt International, Inc. Chemically inert flow control with non-contaminating body
US6505516B1 (en) 2000-01-06 2003-01-14 Rosemount Inc. Capacitive pressure sensing with moving dielectric
US6508129B1 (en) * 2000-01-06 2003-01-21 Rosemount Inc. Pressure sensor capsule with improved isolation
US6520020B1 (en) 2000-01-06 2003-02-18 Rosemount Inc. Method and apparatus for a direct bonded isolated pressure sensor
JP3620795B2 (en) 2000-01-06 2005-02-16 ローズマウント インコーポレイテッド Grain growth in electrical interconnects for microelectromechanical systems.
US6561038B2 (en) 2000-01-06 2003-05-13 Rosemount Inc. Sensor with fluid isolation barrier
US6782754B1 (en) 2000-07-07 2004-08-31 Rosemount, Inc. Pressure transmitter for clean environments
US6612175B1 (en) 2000-07-20 2003-09-02 Nt International, Inc. Sensor usable in ultra pure and highly corrosive environments
US7152478B2 (en) * 2000-07-20 2006-12-26 Entegris, Inc. Sensor usable in ultra pure and highly corrosive environments
US7161476B2 (en) 2000-07-26 2007-01-09 Bridgestone Firestone North American Tire, Llc Electronic tire management system
US8266465B2 (en) 2000-07-26 2012-09-11 Bridgestone Americas Tire Operation, LLC System for conserving battery life in a battery operated device
US6510741B2 (en) 2000-09-06 2003-01-28 Dwyer Instruments, Inc. Manometer having dual pressure sensors
EP1328784B1 (en) 2000-10-24 2006-08-23 Rosemount Inc. In-line pressure transmitter
US6848316B2 (en) * 2002-05-08 2005-02-01 Rosemount Inc. Pressure sensor assembly
JP2004342821A (en) * 2003-05-15 2004-12-02 Renesas Technology Corp Semiconductor device
US6883380B2 (en) * 2003-05-16 2005-04-26 Rosemount Inc Pressure sensor capsule
US7627441B2 (en) * 2003-09-30 2009-12-01 Rosemount Inc. Process device with vibration based diagnostics
US7036381B2 (en) * 2004-06-25 2006-05-02 Rosemount Inc. High temperature pressure transmitter assembly
US7373831B2 (en) * 2004-06-25 2008-05-20 Rosemount Inc. High temperature pressure transmitter assembly
US7258021B2 (en) * 2004-06-25 2007-08-21 Rosemount Inc. Process transmitter isolation assembly
US7347099B2 (en) * 2004-07-16 2008-03-25 Rosemount Inc. Pressure transducer with external heater
US7190053B2 (en) 2004-09-16 2007-03-13 Rosemount Inc. Field device incorporating circuit card assembly as environmental and EMI/RFI shield
JP5312806B2 (en) * 2005-02-28 2013-10-09 ローズマウント インコーポレイテッド Process device diagnostic apparatus and diagnostic method
US8112565B2 (en) 2005-06-08 2012-02-07 Fisher-Rosemount Systems, Inc. Multi-protocol field device interface with automatic bus detection
US20070068225A1 (en) * 2005-09-29 2007-03-29 Brown Gregory C Leak detector for process valve
US7679033B2 (en) * 2005-09-29 2010-03-16 Rosemount Inc. Process field device temperature control
US7287432B2 (en) * 2005-11-17 2007-10-30 Rosemount Inc. Process transmitter with overpressure vent
JP5676100B2 (en) * 2006-04-25 2015-02-25 ローズマウント インコーポレイテッド Pressure sensor using near net shape sintered ceramic
US7953501B2 (en) * 2006-09-25 2011-05-31 Fisher-Rosemount Systems, Inc. Industrial process control loop monitor
US8788070B2 (en) 2006-09-26 2014-07-22 Rosemount Inc. Automatic field device service adviser
JP2010505121A (en) 2006-09-29 2010-02-18 ローズマウント インコーポレイテッド Magnetic flow meter with verification
US7458275B2 (en) * 2007-03-15 2008-12-02 Rosemount Inc. Welded header for pressure transmitter
US7454975B2 (en) * 2007-04-06 2008-11-25 Rosemount Inc. Expansion chamber for use with a pressure transmitter
US8898036B2 (en) * 2007-08-06 2014-11-25 Rosemount Inc. Process variable transmitter with acceleration sensor
US7624642B2 (en) * 2007-09-20 2009-12-01 Rosemount Inc. Differential pressure sensor isolation in a process fluid pressure transmitter
US7590511B2 (en) * 2007-09-25 2009-09-15 Rosemount Inc. Field device for digital process control loop diagnostics
US7484416B1 (en) 2007-10-15 2009-02-03 Rosemount Inc. Process control transmitter with vibration sensor
US7779698B2 (en) * 2007-11-08 2010-08-24 Rosemount Inc. Pressure sensor
US7497123B1 (en) 2007-12-18 2009-03-03 Rosemount Inc. Direct mount for pressure transmitter with thermal management
US8042401B2 (en) * 2008-06-12 2011-10-25 Rosemount, Inc. Isolation system for process pressure measurement
US7814798B2 (en) * 2008-09-17 2010-10-19 P I Components Corporation Diaphragm structure and method of manufacturing a diaphragm structure
US8371175B2 (en) * 2009-10-01 2013-02-12 Rosemount Inc. Pressure transmitter with pressure sensor mount
US9207670B2 (en) 2011-03-21 2015-12-08 Rosemount Inc. Degrading sensor detection implemented within a transmitter
US9010191B2 (en) 2011-12-22 2015-04-21 Rosemount Inc. Pressure sensor module for sub-sea applications
JP5940181B2 (en) 2012-03-06 2016-06-29 ローズマウント インコーポレイテッド Underwater remote seal pressure measurement system
US9052240B2 (en) 2012-06-29 2015-06-09 Rosemount Inc. Industrial process temperature transmitter with sensor stress diagnostics
US9602122B2 (en) 2012-09-28 2017-03-21 Rosemount Inc. Process variable measurement noise diagnostic
US9442031B2 (en) 2013-06-28 2016-09-13 Rosemount Inc. High integrity process fluid pressure probe
US9689769B2 (en) * 2013-07-19 2017-06-27 Rosemount Inc. Pressure transmitter having an isolation assembly with a two-piece isolator plug
US9234776B2 (en) 2013-09-26 2016-01-12 Rosemount Inc. Multivariable process fluid transmitter for high pressure applications
US9459170B2 (en) 2013-09-26 2016-10-04 Rosemount Inc. Process fluid pressure sensing assembly for pressure transmitters subjected to high working pressure
US10260980B2 (en) 2013-09-27 2019-04-16 Rosemount Inc. Pressure sensor with mineral insulated cable
US9423315B2 (en) 2013-10-15 2016-08-23 Rosemount Aerospace Inc. Duplex pressure transducers
US9638600B2 (en) 2014-09-30 2017-05-02 Rosemount Inc. Electrical interconnect for pressure sensor in a process variable transmitter
US9816889B2 (en) * 2015-01-30 2017-11-14 Omega Engineering, Inc. Differential pressure sensing device with overload protection
US10209154B2 (en) * 2015-03-30 2019-02-19 Rosemount Inc. In-line process fluid pressure transmitter for high pressure applications
EP3356777B1 (en) * 2015-09-30 2023-03-01 Rosemount Inc. Pressure transmitter with overpressure protection
US10378987B2 (en) * 2017-03-10 2019-08-13 Honeywell International Inc. Pressure sensor with flow porting having integral flame-proof safety mechanism
US10598559B2 (en) 2017-06-29 2020-03-24 Rosemount Inc. Pressure sensor assembly
EP3769063B1 (en) 2018-05-17 2023-01-04 Rosemount Inc. Measuring element and measuring device comprising the same
CN109752418B (en) * 2019-01-21 2021-11-05 中国科学院上海微系统与信息技术研究所 Miniature thermal conductivity gas sensor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4006640A (en) * 1976-02-06 1977-02-08 Honeywell Inc. Seal for process pressure to current transmitter
US4264889A (en) * 1977-10-26 1981-04-28 Hitachi, Ltd. Pressure transducer
JPS6227637A (en) * 1985-07-29 1987-02-05 Chino Corp Pressure sensor
EP0354479A2 (en) * 1988-08-07 1990-02-14 Nippondenso Co., Ltd. Semiconductor pressure sensor
JPH03194432A (en) * 1989-12-22 1991-08-26 Hitachi Ltd Semiconductor pressure sensor

Family Cites Families (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB705124A (en) * 1952-02-05 1954-03-10 Alltools Ltd Improvements in pipe couplings
US3405559A (en) * 1966-11-07 1968-10-15 United Aircraft Corp Pressure transducer
US4092696A (en) * 1976-12-27 1978-05-30 Borg-Warner Corporation Variable area capacitive pressure transducer with temperature compensation
US4208782A (en) * 1977-12-12 1980-06-24 Kulite Semiconductor Products, Inc. Methods of fabricating transducers employing flat bondable surfaces with buried contact areas
US4196632A (en) * 1978-08-14 1980-04-08 The Boeing Company Dual capacitance type bonded pressure transducer
JPS5817421B2 (en) * 1979-02-02 1983-04-07 日産自動車株式会社 semiconductor pressure sensor
US4236137A (en) * 1979-03-19 1980-11-25 Kulite Semiconductor Products, Inc. Semiconductor transducers employing flexure frames
US4434451A (en) * 1979-10-29 1984-02-28 Delatorre Leroy C Pressure sensors
US4301492A (en) * 1980-01-28 1981-11-17 Paquin Maurice J Pressure-sensing transducer
US4443293A (en) * 1981-04-20 1984-04-17 Kulite Semiconductor Products, Inc. Method of fabricating transducer structure employing vertically walled diaphragms with quasi rectangular active areas
DE3222620A1 (en) * 1982-02-15 1983-08-25 Siemens AG, 1000 Berlin und 8000 München PRESSURE OR PRESSURE DIFFERENCE MEASURING DEVICE WITH A PRESSURE SENSOR DEVICE PROTECTED FROM OVERLOAD
US4479070A (en) * 1983-06-10 1984-10-23 Sperry Corporation Vibrating quartz diaphragm pressure sensor
GB8401848D0 (en) * 1984-01-24 1984-02-29 Carter R E Pressure transducer
US4586108A (en) * 1984-10-12 1986-04-29 Rosemount Inc. Circuit for capacitive sensor made of brittle material
US4603371A (en) * 1984-10-12 1986-07-29 Rosemount Inc. Capacitive sensing cell made of brittle material
US4800758A (en) * 1986-06-23 1989-01-31 Rosemount Inc. Pressure transducer with stress isolation for hard mounting
US4798089A (en) * 1987-03-12 1989-01-17 Rosemount Inc. Isolator apparatus
US4833922A (en) * 1987-06-01 1989-05-30 Rosemount Inc. Modular transmitter
US4790192A (en) * 1987-09-24 1988-12-13 Rosemount Inc. Silicon side by side coplanar pressure sensors
JPH0812123B2 (en) * 1987-11-27 1996-02-07 日本碍子株式会社 Pressure sensor
JPH01301134A (en) * 1988-05-30 1989-12-05 Nippon Beeles- Kk Pressure transmitter
DE3901492A1 (en) * 1988-07-22 1990-01-25 Endress Hauser Gmbh Co PRESSURE SENSOR AND METHOD FOR THE PRODUCTION THEREOF
US5081867A (en) * 1988-09-30 1992-01-21 Nec Corporation Semiconductor sensor
FR2638524B1 (en) * 1988-10-27 1994-10-28 Schlumberger Prospection PRESSURE SENSOR FOR USE IN OIL WELLS
US5022270A (en) * 1989-06-15 1991-06-11 Rosemount Inc. Extended measurement capability transmitter having shared overpressure protection means
US4993754A (en) * 1989-09-29 1991-02-19 Rosemount Inc. Liquid level coplanar transmitter adapter
US5115676A (en) * 1990-01-10 1992-05-26 Setra Systems, Inc. Flush-mounted pressure sensor
JP2718563B2 (en) * 1990-08-28 1998-02-25 日本特殊陶業株式会社 Pressure detector
JP2724419B2 (en) * 1990-08-28 1998-03-09 日本特殊陶業株式会社 Pressure sensor
US5095755A (en) * 1990-11-01 1992-03-17 Rosemount Inc. Isolator for pressure transmitter
US5094109A (en) * 1990-12-06 1992-03-10 Rosemount Inc. Pressure transmitter with stress isolation depression
US5157972A (en) * 1991-03-29 1992-10-27 Rosemount Inc. Pressure sensor with high modules support
WO1992017757A1 (en) * 1991-04-05 1992-10-15 Mark Iv Transducer Corporation Differential pressure device
US5161415A (en) * 1991-04-11 1992-11-10 Mitsubishi Denki K.K. Pressure sensor
US5133215A (en) * 1991-06-19 1992-07-28 Honeywell Inc. Pressure transmitter assembly having sensor isolation mounting
KR0163443B1 (en) * 1991-07-04 1999-03-30 나까오 다께시 Pressure measuring apparatus
US5178015A (en) * 1991-07-22 1993-01-12 Monolithic Sensors Inc. Silicon-on-silicon differential input sensors
US5227068A (en) * 1991-10-25 1993-07-13 Eco-Soil Systems, Inc. Closed apparatus system for improving irrigation and method for its use
JP2896725B2 (en) * 1991-12-26 1999-05-31 株式会社山武 Capacitive pressure sensor
FR2687777B1 (en) * 1992-02-20 1994-05-20 Sextant Avionique CAPACITIVE MICRO SENSOR WITH LOW PARASITIC CAPACITY AND MANUFACTURING METHOD.
US5287746A (en) * 1992-04-14 1994-02-22 Rosemount Inc. Modular transmitter with flame arresting header
JPH05296867A (en) * 1992-04-23 1993-11-12 Hitachi Ltd Differential pressure transmitter
SE515191C2 (en) * 1992-05-05 2001-06-25 Volvo Ab Process for manufacturing a pressure measuring device and pressure measuring device
US5337612A (en) * 1992-06-08 1994-08-16 Quartzdyne, Inc. Apparatus for pressure transducer isolation
JP3415846B2 (en) * 1993-09-24 2003-06-09 ローズマウント インコーポレイテッド Pressure transmitting device isolation diaphragm
US5424650A (en) * 1993-09-24 1995-06-13 Rosemont Inc. Capacitive pressure sensor having circuitry for eliminating stray capacitance

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4006640A (en) * 1976-02-06 1977-02-08 Honeywell Inc. Seal for process pressure to current transmitter
US4264889A (en) * 1977-10-26 1981-04-28 Hitachi, Ltd. Pressure transducer
JPS6227637A (en) * 1985-07-29 1987-02-05 Chino Corp Pressure sensor
EP0354479A2 (en) * 1988-08-07 1990-02-14 Nippondenso Co., Ltd. Semiconductor pressure sensor
JPH03194432A (en) * 1989-12-22 1991-08-26 Hitachi Ltd Semiconductor pressure sensor

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 011, no. 207 (P - 592) 4 July 1987 (1987-07-04) *
PATENT ABSTRACTS OF JAPAN vol. 015, no. 455 (P - 1277) 19 November 1991 (1991-11-19) *

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