| 摘要 |
PURPOSE: To provide an evaluation device for the signal from a current measuring type oxygen sensor to be heated, with which it is possible to use an aged oxygen sensor by compensating the measuring error resulting from a signal of the aged oxygen sensor. CONSTITUTION: A sensor signal evaluating device concerned is composed of a resistance measuring device 20, a closed loop control device 21, and a compensation device 22, wherein the resistance measuring device 20 determines the internal resistance of an oxygen sensor 11 by impressing an AC voltage on the sensor 11, while the control device 21 is formed to control a heater device 18 for the sensor so that the internal resistance of the sensor 11 remains approx. constantly. |
