The working principle and introduction of man nox sensor

Introduction: The English name of the oxygen sensor is LAMBADA SENSOR. It is an engine used to reduce pollutants in the emitted gas. It is one of the important tools for our country to reduce pollution and protect the environment. This article mainly introduces the working principle of nox sensor.

Introduction to nox sensor
The function of the nox sensor is to install it in the engine, and then detect the oxygen concentration in the pollutants emitted by the engine when the engine is working. Once the nox sensor detects the concentration and content of oxygen, it will transmit the oxygen content to the ECU computer in the form of a voltage signal, so that the engine control is closed-loop, and the excessive air content is used as the control target to achieve the maximum conversion efficiency. , so that the pollutants emitted by the engine are purified and transformed.
How nox sensor works
The nox sensor is one of the essential components to reduce the air pollution of the engine. It uses a three-way catalytic converter to catalyze the pollutants in the engine exhaust gas into non-toxic and harmless decomposition products. Not only that, if the engine exhausts The pollutants contained in the air contain CO, HC and NOx and other gases. The decomposition ability of the three-way catalytic converter to these gases drops sharply, or the combustion of the mixed gas out of thin air in the air will also cause the three-way catalytic converter to work inefficiently. At this time, the nox sensor comes into play - it can detect the oxygen concentration in the gas emitted by the engine, and send a FEEDBACK (feedback signal) to the ECU in time, and then the ECU controls the fuel injector through the nox sensor. The efficiency and the amount of fuel injection reduce the air-fuel ratio of the mixture to the theoretical ratio of about 14.7.
When the air-fuel ratio in the mixed gas is lower than the theoretical value of 14.7, this phenomenon means that the oxygen content of the pollutants emitted by the engine is relatively low, and the oxygen-containing ions on the outer side of the ceramic tube of the engine are relatively small, which makes the The voltage signal sent by the nox sensor is about 1.0V; when the air-fuel ratio in the mixture is 14.7, the nox sensor will send out a reference electromotive force with a voltage of 0.4V to 0.5V; however, when the air-fuel ratio of the mixture is 14.7 The value is relatively high. When it exceeds 14.7, the oxygen content in the polluting emissions is relatively high, so there are more oxygen-containing ions inside and outside the ceramic tube in the engine, and the concentration difference is relatively small, resulting in a relatively low electromotive force from the nox sensor. even close to 0.
Through this article, do you have a better understanding of nox sensor and its working principle? I hope everyone can install the nox sensor on the engine of the car and contribute to the national environmental protection!