| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heater-containing-gas-sensor control device capable of preventing damage, deterioration, and a decrease in detection precision in a gas sensor. <P>SOLUTION: When an ignition switch is turned on, a heater starts conducting electricity, so that the temperature of the peripheral part of a gas sensor 15 (the temperature of gas in a gas detection chamber) Ts becomes higher than a predetermined start-up temperature #Ti. Alternatively, at a point of time where a predetermined period of time during which the heater conducts electricity has elapsed since the heater started conducting electricity, the gas sensor 15 is activated. At the same time as or after the gas sensor 15 is activated, off-gas circulation is started. When the ignition switch is turned off, the off-gas circulation is stopped, so that the supply of power to the gas sensor 15 is stopped. In a state that the temperature difference ΔT between the temperature of gas in the gas detection chamber Ts and the temperature of upstream gas Tg is maintained in a predetermined range, the conduction of electricity to the heater is stopped after a predetermined period of time has elapsed since the operation of the gas sensor 15 has been stopped. <P>COPYRIGHT: (C)2009,JPO&INPIT |
