| 摘要 |
An NOx-concentration detecting apparatus enables a user to readily know a record of operating conditions of an NOx sensor. The apparatus includes an NOx sensor, pumping-current control means, constant-voltage application means, NOx-concentration detecting means, a heater and writing means for writing to a recorder variation of at least one parameter selected from a first pumping current value, a second pumping current value, the concentration of oxygen contained in the measurement gas and the concentration of NOx in the measurement gas. Also disclosed is an NOx-concentration detecting apparatus capable of determining the concentration of NOx at a high resolution even when different NOx sensors are used. The NOx-concentration detecting apparatus detects the first pumping current IP1 and the second pumping current Ip2, corrects the detected values based on correction data stored on a floppy disk, and determines the concentration of NOx in the measurement gas using stored standard characteristics. <IMAGE> |
