| 摘要 |
PURPOSE:To attain miniaturization and to enhance accuracy, by obtaining a static pressure signal using the change cycle of a counter and correcting static pressure using the difference pressure signal of the output of an integrator. CONSTITUTION:A first electrode 8 and a second electrode 9 are opposed to a moving electrode 7 and a sealing liquid is allowed to fill to form a first and a second electrostatic capacitors differentially changing corresponding to difference pressure to be detected. A change cycle signal is obtained in a count means Q7 by an amplifying means Q6, a fixed capacitor Ck and selection gate circuits 20, 21. A static pressure signal Ps is calculated on the basis of the temp. T from a temp. sensor 13 and the change cycle signal of a count means Q7 by a static pressure operation circuit 24. In order to correct difference pressure DELTAp with respect to said static pressure signal Ps, operation is performed on the basis of the static pressure Ps, the temp. T and the operation voltage V proportional to the difference pressure DELTAp by a correction operating circuit 25 to output the difference pressure DELTApC after correction.
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