| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas analyzer that uses an adsorptive combustion type gas sensor, capable of reducing noises in a differential waveform of sensor output of measurement gas and representing a sufficient difference in the differential waveform of sensor output due to difference in concentrations. SOLUTION: A bridge voltage applying to a bridge circuit containing a microheater of the adsorptive combustion type gas sensor is controlled. The microheater of the gas sensor is controlled to raise the temperature for 40 milliseconds, at all times. Excessive gas components, moisture, etc. of the gas sensor are burnt off in a preliminary combustion step. The gas sensor is allowed to adsorb a measurement gas in a gas adsorption step of 10 seconds. A sensor output is speedily sampled in a sampling step. A single cycle of the preliminary combustion step, gas adsorption step, and sampling step is repeated four times, and the values corresponding to four times the sensor output are integrated in the same sampling timing. A differential waveform is obtained from the integrated values. COPYRIGHT: (C)2011,JPO&INPIT
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