| 摘要 |
PROBLEM TO BE SOLVED: To allow electromotive force characteristics of a gas sensor to be appropriately shifted.SOLUTION: A CO2 sensor 16 includes: a sensor element 31 having a solid electrolytic layer 32 and a pair of electrodes 33, 34 provided at a position sandwiching a solid electrolytic layer 32, and outputs a signal of electromotive force according to an air fuel ratio of an exhaust gas with the exhaust gas of an engine as a detection object. A microcomputer 41 executes the current application by a constant current circuit 43 based on a demand value of the application current applied to the sensor element 31, and includes: characteristic control means for causing the electromotive characteristics of the sensor element 31 to be shifted; deviation determination means for determining whether or not a deviation of the shift amount of the electromotive force characteristics is generated in a current application state by the constant current circuit 43, and application current correction means for executing the increasing/decreasing correction of the application current by the constant current circuit 43 in order to eliminate the deviation when determined that the deviation of the shift amount is generated.SELECTED DRAWING: Figure 2 |
