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Title:
【発明の名称】圧力トランスジューサの補正装置
Document Type and Number:
Japanese Patent JP3247379
Kind Code:
B2
Abstract:
A two-wire transmitter includes a pressure sensor comprising first and second sensing means each having an impedance value which varies with pressure being measured and with a predetermined environmental condition, such as line pressure or temperature. A fixed impedance has an impedance value which is substantially unchanged by variations in the predetermined environmental condition. A switch alternately connects the fixed impedance into operative relation with the first and second sensing means to derive first and second signals which are each functions of pressure being measured and the predetermined environmental condition. A correction circuit processes the first and second signals, such as by a polynomial series or with a lookup table, to derive a corrected pressure signal. In one form, the sensor senses differential pressure and the predetermined environmental condition is line pressure or temperature, and the first and second signals are functions of both differential pressure and either line pressure or temperature, so the correction circuit derives an indication of differential pressure corrected for variations in either line pressure or temperature. In another form, the sensor measures line pressure and is sensitive to temperature changes, in which case the first and second signals are functions of line pressure and temperature and the correction circuit derives a line pressure signal corrected for variations in temperature.

Inventors:
Flick, Roger El.
Manson, Gregory S.
Application Number:
JP50059994A
Publication Date:
January 15, 2002
Filing Date:
May 17, 1993
Export Citation:
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Assignee:
Rosemount Incorporated
International Classes:
G01L9/00; G01L9/06; G01L9/12; G01L13/06; G01L19/00; G01L19/02; G01L19/04; G01L19/08; G01L27/00; (IPC1-7): G01L13/06
Domestic Patent References:
JP61251714A
JP368831A
JP60138435A
JP62140040A
JP5500716A
Other References:
【文献】米国特許4321832(US,A)
【文献】米国特許4091683(US,A)
Attorney, Agent or Firm:
Michito Hiraki (1 person outside)