Testing of heating power of NOx sensor

eldzhou

Testing of heating power of NOx sensor [Copy link]

Testing of heating power of NOx sensor

Sensors based on the Nerst equation and using zirconium oxide ( YSZ ) as the base need to work at high temperatures. This type of sensor is widely used in the field of automobile exhaust emission detection. When the sensor is working, there are two heating methods, namely external passive heating and internal active heating. Because the method of heating the sensor by relying on the heat of the engine exhaust takes a long time to start, it fails to meet the requirements of the new emission regulations and has now been eliminated by the active heating method.

The active heating sensor has the advantage of fast ignition time, but it increases the difficulty of the sensor's heating and sintering process, and also increases the sensor's heating control circuit. The following are the test and calibration methods and steps for the nitrogen oxide sensor heating circuit:

1. Measure the resistance of the heating resistor and preliminarily predict the required heating voltage and heating pulse width.
2. Connect the eight wires from the NOx sensor to the NOS-12 analyzer as required.
3. The X- axis input of the display is selected as the heating power variable, and the Y -axis input is selected as the current variable of the first oxygen pump.
4. Increase the heating voltage slowly.
5. Apply appropriate pump voltage to the first oxygen pump chamber of the nitrogen oxide sensor.
6. The display will show the curve as shown.
7. Export data to EXECL file for detailed analysis.