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Pressure transducer with integral digital temperature compensation

  • US 4,765,188 A
  • Filed: 11/24/1986
  • Issued: 08/23/1988
  • Est. Priority Date: 11/24/1986
  • Status: Expired due to Term
First Claim
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1. A pressure transducer with integral digital compensation comprising:

  • a pressure sensor assembly including a temperature sensitive element;

    an analog signal conditioning circuit connected to said temperature sensitive element, said circuit providing an output proportional to the temperature of said pressure sensor;

    an analog-to-digital converter connected to receive the output of said analog signal conditioning circuit and providing a digital output signal;

    a read only memory having address lines and a data bus, said address lines being connected to receive said digital output signal from said analog-to-digital converter, and said read only memory being pre-programmed to selectively provide thermal span shift or thermal zero shift correction data on said data bus in response to said digital output signal;

    a digital-to-analog converter having an input connected to the data bus of said read only memory and two selectable outputs, said digital-to-analog converter providing an analog signal output to a selected one of said two outputs corresponding to a correction number on said data bus of said read only memory, one of said two outputs being connected to said pressure sensor assembly to provide a thermal span shift compensation;

    timing control means connected to said analog-to-digital converter, to said read only memory, and to said digital-to-analog converter for controlling the sampling of the output signal from said analog conditioning circuit by said analog-to-digital converter and for alternately selecting thermal span shift or zero shift data from said read only memory and one or the other of the two outputs of said digital-to-analog converter; and

    amplifier means connected to said pressure sensor assembly for amplifying an output voltage from said assembly, the other of said two outputs of said digital-to-analog converter being connected to said amplifier means to modify the amplified voltage from said pressure sensor assembly to compensate for thermal zero shift.

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