PARTICULATE SUBSTANCE DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide a particulate substance detector capable of detecting a particulate substance with high accuracy by using a sensor circuit by simple structure.

SOLUTION: A particulate substance detector 100 includes: a voltage application circuit 22 which applies a voltage signal of a sine wave obtained by syntonizing a voltage signal of a square wave by a lowpass filter whose Q value is 1.5-3; a current voltage conversion circuit 26 which converts the applied voltage into current; a detection circuit 23 which decomposes output of the current voltage conversion circuit 26 into orthogonal components by synchronous detection of two or more phases to be detected; and characteristic measurement means 20 which has two or more calibration elements 24a and 24b electrically connected to the voltage application circuit 22 and the current voltage conversion circuit 26 at a state that the calibration elements can be switched to a pair of measurement electrodes 12a and 12b. The detector calculates a calibration matrix Q of the current voltage conversion circuit 26 from two or more calibration detection values measured by using the two or more calibration elements 24a and 24b, respectively and original true values of the two or more calibration elements, and calibrates a detection value which is measured between the pair of measurement electrodes 12a and 12b.

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