The oxygen sensor works like a battery, and the zirconia element in the sensor acts like an electrolyte. The basic working principle is: under certain conditions (high temperature and platinum catalysis), the difference in oxygen concentration between the inner and outer sides of the yttrium oxide is used to generate a potential difference, and the larger the concentration difference, the larger the potential difference. The content of oxygen in the atmosphere is 21%. The exhaust gas after concentrated mixing combustion does not contain oxygen. The exhaust gas generated after the combustion of the lean mixture or the exhaust gas generated by the lack of fire contains more oxygen, but still less than the oxygen in the atmosphere. More.
Under high temperature and platinum catalysis, the oxygen attached to the oxygen sensor is exhausted, so that a voltage difference is generated, the output voltage of the rich mixture is close to 1V, and the lean mixture is close to 0V. According to the voltage signal of the oxygen sensor, the air-fuel ratio is controlled to adjust the injection pulse width, so the electronic sensor of the oxygen sensor controls the key sensor of the fuel metering. The oxygen sensor can only fully reflect the characteristics when it is at a high temperature (the end reaches 300 ° C or higher), and the voltage can be output. It reacts most rapidly to changes in the mixture at about 800 °C.