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Apparatus using a feedback network to measure fluid pressures

  • US 5,604,315 A
  • Filed: 01/12/1995
  • Issued: 02/18/1997
  • Est. Priority Date: 01/12/1995
  • Status: Expired due to Fees
First Claim
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1. An apparatus for measuring a characteristic of a liquid column in a cell having a blanket region overlying said liquid column said blanket region being characterized by a blanket pressure P1, comprising:

  • A. first pressure sensing means for differentially generating a first signal representative of the pressure of said cell at a first height H1 with respect to a reference pressure;

    B. second pressure sensing means for differentially generating a second signal representative of the pressure of said cell at a second height H2 with respect to said reference pressure, said second height being lower than said first height, andC. feedback means for substantially equalizing said reference pressure with the pressure of said cell at one of said first and second heights.

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