NOx Sensor

About NOx Sensor

In order to respond to the recent strict NOx regulation, precise NOx detection has been requested.

NOx Sensor for NOx aftertreatment system

The NOx sensor is part of the NOx reduction aftertreatment system used in diesel vehicles with urea based SCR systems. The sensor located upstream of the SCR catalyst directly measures the engine-out NOx gas concentration, which helps determine the optimum amount of urea injection. The NOx sensor downstream of the SCR catalyst is used to monitor the performance of the catalyst. Accurate NOx measurement is in high demand to comply with increasingly strict NOx emissions regulations. The NOx sensor is also capable of measuring O2 concentration, just like a wide range air-fuel sensor.

SCR application
Result of NOx measurement pre / after SCR

Main Products



This sensor can simultaneously measure the concentration of and NOx in the exhaust. By enabling NOx control in lean burn and diesel applications, the sensor contributes to better fuel economy and cleaner air.


  • Real time, simultaneous measurement of NOx and O2 concentration
  • Fast response
  • Fully sealed waterproof design does not require external reference air
  • High water resistance
  • High toxicity resistance
  • Early activation