| 摘要 |
PROBLEM TO BE SOLVED: To simplify calculation of determining a constant constituting a function f(P) previously in calibration and to reduce labor of the calibration, in a pressure measuring device that detects sensor capacitances C1(P) and C2(P) varying differentially due to displacement by pressure difference P between both surfaces of a diaphragm as time values T1(P) and T2(P) proportional to them and measures and calculates a measured pressure difference P from a linearizing function f(P) using the detected time values. SOLUTION: In this measuring device, the measured pressure difference P is calculated on the condition where the linearizing function f(P)=[äT1(P)-TS1}-äT2(P)-TS2}]/[äT1(P) TS1}+äT2(P)-TS2}] is linear with respect to the pressure difference P. TS1 and TS2 are constants calculated and set in the calibration, but can be calculated by solving a simple linear expression using time values T1(P0), T1(P1), T1(P2), T2(P0), T2(P1) and T2(P2) measured under three existing reference pressure differences P0, P1 and P3. COPYRIGHT: (C)2006,JPO&NCIPI
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