CORRECTION FOR A PRESSURE TRANSDUCER
    4.
    发明申请
    CORRECTION FOR A PRESSURE TRANSDUCER 审中-公开
    压力传感器的校正

    公开(公告)号:WO9324818A3

    公开(公告)日:1994-02-03

    申请号:PCT/US9304673

    申请日:1993-05-17

    Applicant: ROSEMOUNT INC

    CPC classification number: G01L27/005 G01L9/065 G01L9/125 G01L19/02

    Abstract: A two-wire transmitter includes a pressure sensor (5; 160) comprising first (11; R9, R10) and second (13; R11, R12) 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 (CL1, CL2; R13) has an impedance value which is substantially unchanged by variations in the predetermined environmental condition. A switch (208, 210, 212, 214; 234, 238) 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 (206) processes the first and second signals, such as by a polynomial series or with a lookup table, to derive a corrected pressure signal.

    9.
    发明专利
    未知

    公开(公告)号:MX9303098A

    公开(公告)日:1994-03-31

    申请号:MX9303098

    申请日:1993-05-26

    Applicant: ROSEMOUNT INC

    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.

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