What's The Working Principle of Ceramic Oxygen Sensors on Vehicles
Oxygen sensors on vehicles are indispensable components, for their two main functions, one is to detect oxygen in exhaust, transmit result to ECU and control fuel injection, the other is to monitor catalytic system working, to not emit hazardous substance over limit of regulations. Therefore there at least two oxygen sensors installed on the engine, the former is front oxygen sensor and the latter is back oxygen sensors, as shown in the figure below. For some engines, more than two oxygen sensors are installed to get higher reliability, two front O2 sensors + one back O2 sensor, or even two front O2 sensors + two back O2 sensors. Oxygen sensor on vehicles is working at high temperature, and directly contacts with corrosive gases, ceramic material is used to produce the sensor measuring chip. There are two types of ceramic material to produce measuring chip, titanium oxide (titania, TiO2) and zirconium oxide (zirconia, ZrO2). TiO2 ceramic resistanc...