| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas-detecting device with high sensitivity, which can detect odorous gas, in a short period of time. SOLUTION: The gas-detecting device is equipped with a gas-sensitive body 4 which is made up by adding a precious metal catalyst to a metal oxide semiconductor changing its electrical resistance value, in response to object gas to be detected including at least the smelly gas; an electrode 3a serving as a heater, which is embedded in the gas-sensitive body 4 and heats the gas-sensitive body 4; and a microcomputer 11 which controls the amount of heat of the electrode 3a serving as the heater, such that a high-temperature period of time, when the gas-sensitive body 4 is heated at a first set temperature, and a low-temperature period of time, when the gas-sensitive body 4 is heated at a second set temperature lower than the first set temperature, are repeated alternately, and which detects the gas concentration value of the object gas to be detected, based on the electrical resistance value of the gas-sensitive body 4. The microcomputer 11 detects the gas concentration of the odorous gas, based on the variations in the electrical resistance value for the low-temperature period of time in the atmosphere of the gas to be detected, in relation to an electrical resistance value for the low-temperature period of time in cleaned air. COPYRIGHT: (C)2006,JPO&NCIPI
|
