GAS DETECTOR AND GAS DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To detect a lowered concentration of gas components generated in case of a fire at a higher sensitivity than do gases such as carbon monoxide and methane and furthermore, identify gases and ethanol turned to miscellaneous gases generated during the fire individually with one gas sensor. SOLUTION: A heater drive circuit 5 performs an ON drive or OFF drive of a first gas sensor 1 by a first pulse drive signal in which the total of the ON operation time and the first OFF operation time set longer enough than the ON operation time is equivalent to the cycle thereof and performs an ON drive or OFF drive of a second gas sensor 5 by a second pulse drive signal in which the total of the ON operation time and the second OFF operation time set longer than the first OFF operation time is equivalent to the cycle thereof. The first sensor output detection part 13a detects the first sensor output value of the first gas sensor 1 at the ON operation time and the second sensor output detection part 13b detects the second sensor output value of the second gas sensor 5 at the ON operation time. A gas identification part 15 compares the first sensor output value detected with the second sensor output value to identify the type of gases based on the result of the comparison.