| 摘要 |
PROBLEM TO BE SOLVED: To prevent wrong determinations due to humidity when performing gas detection, by using an adsorption/combustion type micro-gas sensor, on the basis of determination data obtained by subtracting reference data from actual measurement data. SOLUTION: The adsorption/combustion type gas sensor outputs peak waveforms immediately after the pulse-on of a drive pulse by adsorbing polar gas, and outputs waveforms, which then lower to be stabilized at a prescribed level, till the pulse-on period is ended. Based on the sensor output obtained from the gas sensor before starting measurement, reference data which are not affected by a gas to be detected are fetched. Sensor outputs, obtained on and after the start of measurement, are fetched as actual measurement data. Determination data are calculated by subtracting the reference data from the measurement data. A voltage level in a contact combustion range in the determination data is observed, the voltage level corresponding to an output portion of waveform stabilized at a prescribed level during the pulse-on period. When the voltage level in the combustion range exceeds a prescribed voltage level, it is determined that the gas is a polar gas. COPYRIGHT: (C)2005,JPO&NCIPI
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