Nox Sensor 2294291,5WK97401,2064769,2247381 for SCANIA

What does a NOX sensor do?
The NOx sensor not only monitors the level of the oxides of nitrogen being released into the air, but it also plays an essential role in controlling it through the Selective Catalytic Reduction (SCR) system in diesel vehicles.
The NOx sensor is a key part of this system, which also includes the SCR catalyst, Diesel Particulate Filter (DPF), and turbocharger amongst others. If the NOx sensor detects too much NOx gases being emitted, it sends that information to the SCR system, which then adjusts the output to a level that’s compliant with emission regulations.
How does a NOX sensor work?
The sensor is made up of a Nernst cell with a current flowing through. This corrects the air/fuel ratio to λ=1. A second cell, usually made of ceramic with a layer of rhodium, breaks down the oxides of nitrogen into nitrogen and oxygen. The NOx controller – usually closely positioned to the NOx sensor – calculates the level of oxides of nitrogen present in the exhaust gas, and sends that data to the SCR controller. The SCR controller then adjusts the amount of diesel exhaust fluid injected into the SCR catalyst, which in turn transforms excess oxides of nitrogen into water and nitrogen.