| 摘要 |
PROBLEM TO BE SOLVED: To provide an intermittent driving combustible gas detection device capable of selecting automatically and surely a sensor corresponding to the concentration of the combustible gas to be measured regardless of the concentration of the combustible gas. SOLUTION: In this combustible gas detection device for measuring the concentration of the combustible gas intermittently only during a detection period by switching a low-concentration domain detection part 2 equipped with a catalytic combustion type gas sensor to/from a high-concentration domain detection part 1 equipped with a heat conduction type gas sensor by a switching means 5, an oxygen sensor 3 is provided, and the high-concentration domain detection part 1 is selected by the switching means 5 when some case is detected, between a case wherein a detection output from the low-concentration domain detection part 2 exceeds a prescribed value wherein a normal operation of the catalytic combustion type gas sensor S2 is guaranteed, a case wherein it is not detected that the low-concentration domain detection part 2 reaches a stable state during its operation period, and a case wherein the oxygen concentration by the oxygen sensor 3 is below a specified value. COPYRIGHT: (C)2007,JPO&INPIT
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