NOx sensors

NOx sensors are usually installed in the exhaust system of engines, and their working principle is based on solid electrolyte oxygen concentration difference batteries. When oxygen and nitrogen oxides in the exhaust gas reach the diffusion chamber of the sensor through the porous diffusion layer, the oxygen pump inside the sensor will pump oxygen into the diffusion chamber, so that the oxygen concentration in the diffusion chamber is the same as that in the atmosphere. At the same time, nitrogen oxides in the exhaust undergo chemical decomposition in the diffusion chamber, producing nitrogen and oxygen. The sensor determines the concentration of nitrogen oxides in the exhaust gas by measuring the difference in oxygen concentration inside and outside the diffusion chamber.