NOx sensor

New NOx sensors – technologies that protect the environment

NOx sensors, or nitrogen oxide sensors, are a key component of emission control systems in modern internal combustion vehicles. Their main task is to monitor the amount of nitrogen oxides in the exhaust gases, which allows fine-tuning of engine operation and the emission reduction system. They are part of the SCR (Selective Catalytic Reduction) system, the function of which is to reduce the emission of harmful substances contained in exhaust gases into the atmosphere.

At Arcoore we offer a wide selection of NOx sensors, both new and remanufactured, for all makes of trucks and commercial vehicles. In our offer you will find NOx sensors for brands such as Scania, DAF, Mercedes, Cummins, Solaris, man, Renault, Volvo.

NOx sensor – what is it used for?

Nitrogen oxides (NOx) are one of the most dangerous components harmful to the atmosphere. In high concentrations they can be very dangerous to health. Among other things, they are formed in the combustion process in the engine and are then expelled through the exhaust system. Taking into account their enormous harmfulness to the environment, truck manufacturing companies are trying to design exhaust gas recirculation systems in such a way as to minimize the emission of harmful substances. In response to these threats, vehicle manufacturers have introduced modern emission control systems, in which NOx sensor plays a key role .

The NOx sensor is designed to measure the concentration of the amount of the most important nitrogen oxides in the exhaust gas. These include nitrogen oxide (NO) and nitrogen dioxide NO2. Depending on the vehicle model and the design of the SCR system, they are placed in front of or behind the catalytic converter.

With NOx sensors, you can:

• pre-diagnose problems with the operation of the exhaust aftertreatment system;
• find out when to perform maintenance on it;
• replace the correct components;
• add ad blue to the tank.

The target function of the entire system is to clean the exhaust gas of excess harmful substances and ensure the proper operation of the drive unit. Thanks to the proper functioning of NOx sensors, it is also possible to meet exhaust emission standards, which translates into environmental protection and avoidance of penalties associated with exceeding emission limits.

A faulty NOx sensor – what can it cause?

A defective nitrogen oxide sensor will cause the composition of the exhaust gas to be suboptimal, with excessive amounts of harmful substances being emitted into the atmosphere. In addition to this, the proper operation of the engine, as well as increased fuel combustion can be disrupted .

Nitrogen oxide sensors are unfortunately prone to mechanical and thermal damage primarily due to their location. The efficiency of the sensor should start by checking the condition of the wiring. It may happen that damaged cables are responsible for its malfunction. The sensor transmits information to the on-board diagnostic system.

Most often, the on-board computer will signal the problem with an engine light. Often the car will automatically reduce engine power. Given that the check engine light can also signal other faults, it is necessary to perform computer diagnostics. If the service finds that the errors indicate that the NOx sensor is defective, it should be replaced.

NOx sensor – how does it work?

NOx sensor is located directly in the exhaust system of the vehicle, it is used to continuously measure the NOx (nitrogen oxides) content in the exhaust gases of cars. It then sends the information to the engine controller. The controller, on the basis of the information received, controls the operation of the engine and other elements such as Adblue dosing in such a way that there are as few harmful NOx components as possible in the exhaust gases emitted.

Nitrogen oxide sensors have an active electrode, which thanks to catalysis separates nitrogen and oxygen from each other. There are two chambers in the sensor. In the first, the oxygen content is maintained at about 10 ppm. In contrast, it is in the second chamber that NOx catalysis takes place, resulting in the separation of oxygen and nitrogen. A current that is proportional to the NOx concentration is used to maintain the oxygen-free platinum-rhodium electrode environment . It is this current that sends the measurement signal.

How to check if the NOx sensor is working properly?

A faulty NOx sensor can cause an increase in harmful emissions, increased fuel consumption and even a reduction in vehicle power. If you suspect that the NOx sensor is not working properly, it is worthwhile to perform diagnostics to avoid costly repairs and operational problems.

• Computer diagnostics – one of the most effective ways to check the correct operation of the NOx sensor is to connect the vehicle to a diagnostic computer. In modern trucks, construction and agricultural machinery, the ECU (Electronic Control Unit) system monitors the operation of the sensor and records any errors,
• Verification of wiring – often sensor problems are due to damaged wires or connectors. A review of the condition of the wiring can help rule out connection problems.
• Measure sensor voltage – NOx sensors generate an electrical signal proportional to the amount of nitrogen oxides in the exhaust gas. If the sensor is defective, it may generate erroneous values or not transmit a signal at all. To check whether the sensor is working properly, you can perform a test with an electrical meter
• Replacement test – if possible, you can briefly install a working sensor in place of the suspect one to see if the problem goes away.

Why do we use nitrogen oxide sensors?

As a result of the need to modify vehicles so that their operation is increasingly less harmful to the atmosphere, the early 21st century saw the use of exhaust emission reduction systems in automotive and commercial vehicles. Vehicles manufactured today must meet stringent emission standards. The environmental friendliness of the NOx sensor lies not only in the reduction of harmful substances in fuels, but also in the reduction of combustion and optimization of engine operation.

Nitrogen oxide sensor for trucks

Environmental protection is also of great importance in the automotive industry. NOx sensors installed in trucks and industrial vehicles are used to measure the content of nitrogen oxides in the exhaust gases of cars. They allow to control the level of emission of harmful gases into the environment, which, in the era of high public awareness, makes them an element that customers often ask us about. Arcoore offers nitrogen oxide sensors for many makes of vehicles including NOx sensor for: Scania, DAF, Mercedes, Cummins, Solaris, man, Renault, Volvo.

What is the function of the NOx sensor?

The nitrogen oxide sensor controls the engine’s operation so that only particles of pure nitrogen, which is harmless to health, are present in the exhaust gas. Its operation is crucial for meeting emission standards such as Euro 6, which require a significant reduction in nitrogen oxides. The NOx sensor’s main functions are:

• monitoring the nitrogen oxide content at the outlet of the absorption catalyst,
• monitoring of nitrogen oxide content before and after the selective reduction catalyst (SCR),
• monitoring carried out by the sensor and control element to control the wear of the catalyst and other components,
• through precise adjustment of engine operating parameters, the NOx sensor helps reduce fuel consumption and improve the efficiency of the drive unit
• proper operation of the NOx sensor reduces the risk of damage to the catalytic converter and other components of the exhaust aftertreatment system.

NOx sensor – characteristics

The NOx sensor can be placed directly in the high-temperature exhaust gas, thus obtaining highly accurate readings of exhaust parameters.

The NOx sensor is integrated into the control unit, ensuring independent operation of the sensor.

Direct connection to the ECU via an integrated electronic circuit is possible.

Digital data transmission capability provides a good solution for use with the vehicle’s OBD on-board diagnostics system.

NOx sensors in Arcoore’s offer – quality and reliability.

In our offer you will find high-quality replacements for original NOx sensors for trucks and other commercial vehicles.

Get in touch with us!

If you have not found the NOx sensor you are looking for, or do not have the OE number of the part – nothing lost, contact us, we will find it for you.