FR2373038A1 - Emetteur a capacite, a deux fils - Google Patents

Emetteur a capacite, a deux fils

Info

Publication number
FR2373038A1
FR2373038A1 FR7736351A FR7736351A FR2373038A1 FR 2373038 A1 FR2373038 A1 FR 2373038A1 FR 7736351 A FR7736351 A FR 7736351A FR 7736351 A FR7736351 A FR 7736351A FR 2373038 A1 FR2373038 A1 FR 2373038A1
Authority
FR
France
Prior art keywords
transmitter
capacitance
probe
wire
reference capacitor
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
FR7736351A
Other languages
English (en)
Other versions
FR2373038B1 (fr
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robertshaw Controls Co
Original Assignee
Robertshaw Controls Co
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 Robertshaw Controls Co filed Critical Robertshaw Controls Co
Publication of FR2373038A1 publication Critical patent/FR2373038A1/fr
Application granted granted Critical
Publication of FR2373038B1 publication Critical patent/FR2373038B1/fr
Granted legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/24Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying capacitance
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

L'invention concerne un émetteur à convertisseur de capacité en courant, relié à la source d'alimentation et à un appareil indicateur ou enregistreur par deux fils. Il comporte une sonde à capacité variable et un condensateur de référence. Un discriminateur compare les vitesses de charge de la capacité de la sonde et du condensateur de référence et délivre un courant de sortie qui varie en fonction de la différence entre ces vitesses. L'émetteur comporte également des circuits de réglage de zéro et de déviation totale de l'appareil de mesure associe. L'invention s'applique notamment à des mesures de variables telles que des niveaux, des pressions ou des proximités.
FR7736351A 1976-12-03 1977-12-02 Emetteur a capacite, a deux fils Granted FR2373038A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/747,403 US4145619A (en) 1976-12-03 1976-12-03 Two wire capacitance transmitter

Publications (2)

Publication Number Publication Date
FR2373038A1 true FR2373038A1 (fr) 1978-06-30
FR2373038B1 FR2373038B1 (fr) 1984-03-09

Family

ID=25004913

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7736351A Granted FR2373038A1 (fr) 1976-12-03 1977-12-02 Emetteur a capacite, a deux fils

Country Status (5)

Country Link
US (1) US4145619A (fr)
JP (1) JPS6027076B2 (fr)
DE (1) DE2753884A1 (fr)
FR (1) FR2373038A1 (fr)
GB (1) GB1561947A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981000620A1 (fr) * 1979-08-29 1981-03-05 List H Transducteur de mesure capacitif
FR2486232A1 (fr) * 1980-07-01 1982-01-08 Hokushin Electric Works Dispositif de conversion de deplacement de type capacitif

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE436936B (sv) * 1981-01-29 1985-01-28 Asea Ab Integrerad kapacitiv givare
US4525792A (en) * 1982-03-29 1985-06-25 Smiths Industries Public Limited Company Unidirectional capacitive fluid-gauging systems
US5083091A (en) * 1986-04-23 1992-01-21 Rosemount, Inc. Charged balanced feedback measurement circuit
US4791352A (en) * 1986-07-17 1988-12-13 Rosemount Inc. Transmitter with vernier measurement
US4783659A (en) * 1986-08-22 1988-11-08 Rosemount Inc. Analog transducer circuit with digital control
US4748852A (en) * 1986-10-10 1988-06-07 Rosemount Inc. Transmitter with an improved span adjustment
US5135485A (en) * 1991-02-25 1992-08-04 Louis Cohen Capacitance-type fluid level sensor for i.v. and catheter bags
US5485092A (en) * 1991-08-01 1996-01-16 Fortin; Gabriel Method and device for electrostatically investigating surface and sub-surface structures
US5237285A (en) * 1991-10-18 1993-08-17 Rosemount Inc. Method and apparatus for capacitance temperature compensation and manufacturability in a dual plate capacitive pressure transmitter
US5838241A (en) * 1996-12-18 1998-11-17 Robertshaw Controls Company Liquid level transmitter
US6516672B2 (en) 2001-05-21 2003-02-11 Rosemount Inc. Sigma-delta analog to digital converter for capacitive pressure sensor and process transmitter
GB0121418D0 (en) * 2001-09-04 2001-10-24 Smiths Group Plc Capacitance measuring systems

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3543046A (en) * 1969-04-14 1970-11-24 Fisher Governor Co Capacitance-measuring techniques
FR2205669A1 (fr) * 1972-11-03 1974-05-31 Robertshaw Controls Co

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3482234A (en) * 1965-06-22 1969-12-02 Bendix Corp Signal comparator for minimizing nuisance failure alarms
US3555534A (en) * 1967-03-10 1971-01-12 North American Rockwell Proximity detector with a sensing probe
FR1526273A (fr) * 1967-04-13 1968-05-24 Schlumberger Instrumentation Dispositif pour la mesure des condensateurs électriques
US3612997A (en) * 1970-02-18 1971-10-12 John Paulkovich Capacitor apparatus including a reference capacitor for controlling the current flow through a capacitance being measured
US3829850A (en) * 1971-12-17 1974-08-13 Tyco Laboratories Inc Proximity detector

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3543046A (en) * 1969-04-14 1970-11-24 Fisher Governor Co Capacitance-measuring techniques
FR2205669A1 (fr) * 1972-11-03 1974-05-31 Robertshaw Controls Co

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981000620A1 (fr) * 1979-08-29 1981-03-05 List H Transducteur de mesure capacitif
EP0025029A1 (fr) * 1979-08-29 1981-03-11 List, Hans Dispositif de pont de mesure capacitif
US4481465A (en) * 1979-08-29 1984-11-06 Hans List Capacitive measuring transducer
FR2486232A1 (fr) * 1980-07-01 1982-01-08 Hokushin Electric Works Dispositif de conversion de deplacement de type capacitif

Also Published As

Publication number Publication date
GB1561947A (en) 1980-03-05
JPS6027076B2 (ja) 1985-06-27
JPS5370853A (en) 1978-06-23
DE2753884A1 (de) 1978-06-08
US4145619A (en) 1979-03-20
FR2373038B1 (fr) 1984-03-09

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Legal Events

Date Code Title Description
ST Notification of lapse