Smart NOx Sensor

In 1993 NGK INSULATORS LTD. started the development of a NOx sensor to be used in automotive field of passenger cars and heavy duty diesel applications. In order to realize the NOx sensor concept, NGK used Thick Film ZrO2 Technology, which had already been proven.
NGK was the first manufacturer in the world to apply this technology in oxygen sensors starting in 1987. The actual commercial type of Smart NOx Sensor is a joint development of NGK INSULATORS LTD and Continental AG.
Both companies combined their specific know how of sensor element, assembly technology (NGK INSULATORS LTD) and electronics (Continental AG). The first application in the automotive field started 2002.
In 2010 NGK and Continental received the Automotive News PACE Award for their Smart NOx Sensor.

Key functions of the Smart NOx Sensor
The sensor measures the NOx concentration, the linear A/F-ratio and binary Lambda in the exhaust gas. These key functions allow:

  • to control different types of exhaust gas aftertreatment sub-systems for both gasoline and diesel engines
  • to comply with OBD requirements


  • Lean burn gasoline engines and diesel engines
  • Passenger Cars and Light/Heavy Commercial Vehicles
  • Off-road Application Tier 4
  • Stationary engines and others


  • High accuracy measurement of the NOx concentration in exhaust gas
  • Helps to achieve world wide emission legislation, such as EU/US/JP, BRIC
  • Fulfills On-board diagnosis requirements (OBD)