| 摘要 |
PURPOSE:To discriminate a slight amt. of CO from a reducing gas or combustible gas and to detect the same with a single sensor by combining a sensitive body having selecting sensitivity with H2 and CO and oxidation catalyst which adsorbs H2. CONSTITUTION:The sensitive body 2, an insulating layer 3, a heater 4 and an oxidation catalyst 5, etc., are provided. Gaseous H2 is adsorbed to the catalyst 5 when gaseous CO is applied together with the reducing gas or combustible gas to the element. The gases, except the gaseous H2, which are not adsorbed by the catalyst 5 contact the sensitive body 2 next. Since the sensitive body 2 has the selective sensitivity only to the gaseous H2 and the gaseous CO, said body has no sensitivity even if the reducing gas or combustible gas except said gases contacts the same. The gaseous H2 is trapped by the adsorption effect of the catalyst 5 in this stage. In the end, the gas which contacts the sensitive body 2 is only the gaseous CO and the gaseous CO is detected as a change of the electric resistance of the sensitive body 2. The effect of the catalyst 5 to adsorb the gaseous H2 increase if the catalyst 5 is heated by a hater 5. The gaseous CO is thus detected with high sensitivity.
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