| 摘要 |
PROBLEM TO BE SOLVED: To detect the deterioration of an oxygen sensor, especially the deterio ration of a heating heater, regardless of the combustion or non-combustion state, or the oxygen concentration while using equipment. SOLUTION: This device is equipped with a power source part E for applying a heating voltage to the heater H of this oxygen sensor S, a heater voltage detection part En for detecting the heater voltage applied to the heater, a heater current detection part In for detecting the heater current flowing in the heater H, a dynamic resistance operation part Rd01 for operating periodically the dynamic resistance of the heater H from the detected heater voltage and heater current, a dynamic resistance increase rate operation part Rd02 for acquiring the change with age of the operated dynamic resistance increase, and an exchange time estimation part CHP for estimating the exchange time of the oxygen sensor S based on the dynamic resistance increase rate. |
