| 摘要 |
PROBLEM TO BE SOLVED: To provide a flammable gas detector and a flammable gas detecting method made to precisely detect the flammable gas while considering the fluctuation of the thermal conductivity of the atmosphere to be detected depending on the humidity of the atmosphere. SOLUTION: Both the constant temperature control circuits 230, 240 control both the heating resistors 211, 221 exposed to the measurement spaces to mutually different constant temperatures by controlling currents. The thermometric resistor 390 generates the atmospheric temperature in the measurement space as the temperature voltage. Both the operational amplifier circuits 250, 260 amplify both the outputs from both the bridge circuits 210, 220 into the potential difference of both the differential amplifiers. The microcomputer 270 calculates the ratio of both the potential difference as the voltage difference, calculates the humidity based on the relation among the humidity, voltage ratio, and the temperature voltage, and the concentration of flammable gas in the atmosphere to be detected is calculated based on the relation among the concentration of the flammable gas in the measurement space, potential difference of differential amplifier of the operation amplifier circuit 260, and humidity and temperature voltage. COPYRIGHT: (C)2007,JPO&INPIT
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