| 摘要 |
PROBLEM TO BE SOLVED: To obtain a detecting apparatus which prevents the aggravation of its detecting accuracy caused when an unburned component in a gas to be measured is stuck to an electrode for oxygen-concentration measurement. SOLUTION: A detection part 550 in an NOx sensor 500 is provided with a pump cell 582, for measurement, which is composed of a first solid electrolyte layer 552 as well as a detecting electrode 580 and a reference electrode 581 which are installed on its surface and its rear surface. When an electronic control unit(ECU) judges that an unburned component which is stuck to the detecting electrode 580 reaches a prescribed amount, a voltage for electrode treatment is applied across both electrodes 580, 581. Thereby, oxygen inside a reference-gas introduction space 580 is pumped to the detecting electrode 580 from the reference electrode 580. The unburned component which is stuck to the detecting electrode 580 is reacted with the pumped oxygen, and it is burned and removed. |
