| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas sensor which houses a sensor element having a heater and a circuit board in the same housing part and prevents overheating of the circuit board.SOLUTION: A gas sensor comprises: a sensor element 10 having a detection part 11 and a heater 200; a circuit board 20 mounted with processing means 20A for processing output signals from the sensor element and heater energization control means 20B for controlling the energization of the heater so as to maintain the temperature of the sensor element at a first temperature during a detection period of concentration of a specific gas by the sensor element; and a housing part 60 which houses the sensor element and the circuit board. On the circuit board, a temperature sensor 25 and threshold value determination means 20C for determining whether the temperature of the circuit board exceeds a threshold value are mounted. If it is determined that the temperature of the circuit board exceeds the threshold value, the heater energization control means stops the energization of the heater or forcibly controls the energization of the heater so that the temperature of the circuit board becomes lower than the threshold value. |
