Broadband sensor ZFAS-U2 (für L9780 ASIC)

Design of Broadband Lambda sensor

Protection tube

The protective metal tube is designed to allow good gas contact with the element whilst protecting the sensor element from solid particles in the exhaust. Importantly it also protects the element from contact with any water which may be present in the exhaust system. Water vapour, a product of the combustion process, may condense in the exhaust pipe and if contact with the hot ceramic element occurs damage can result due to thermal shock (rapid change in temperature).

Planar element with heater

The planar element of an NTK broadband lambda sensor is comprised of multiple layers. Along with a pump cell and a measurement cell, it also has an integrated heater.

Element holder

The element holder provides a secure location of the ceramic element and importantly protects it from vibration.


The sensor is installed with the hexagon using the correct tightening torque.


In order to ensure that no moisture penetrates into the sensor, the cables are provided with a rubber seal on the outside. This rubber seal is pressed in over the sensor housing.

Connecting cable

The sensor is connected to the control unit through the connecting cable. The control unit regulates the pump cell and measures the necessary pump flow and evaluates it for the lambda regulation.