| 摘要 |
PURPOSE:To shorten the dead time at the time of load driving, in a CO gas detector, by keeping a gas sensor at a low temperature region when the detected load is operating, and shortening the sampling interval of the output signal of the sensor. CONSTITUTION:A sensor 10 is heated to 350 deg.C based on a high temperature heating signal TH of a timer 2, and heat cleaning is performed. Then, the temperature of the sensor 10 is kept at 80 deg.C. The square of the concentration of CO of the output signal obtained by the sensor 10 based on a sampling signal T1 is sampled. Input to an integrating circuit 46 comprising an up and down counter is made possible by the T1 signal from the timer 2. An adding signal S1 to a counter 22 is added. By subtracting signal T2 from the timer 2, 1 digit is subtracted. The average value of the CO concentration for a long time is monitored. When the output of the integrating circuit 46 becomes the specified value or more, a buzzer 52 is driven. When the buzzer 52 is driven, the sampling interval is shortened by a T3 signal from the timer 2. The temperature of the sensor 10 is kept at a low temperature region. |
