Thick-Film Zirconia Air-Fuel Ratio Sensor with a Heater for Lean Mixture Control Systems 850379
This paper describes the design and operation of a thick-film zirconia air-fuel ratio sensor with a heater. This sensor is composed of two zirconia plate cells, a stoichiometric cell and a lean cell, laminated on the platinum heater. It is fabricated as one body using a thick-film process. The pair of cells has a gas diffusion chamber and a slit type gas diffusion aperture.
The sensing principle is based on the rate-determining diffusion of oxygen molecules at the gas diffusion aperture. By using an oxygen pumping phenomenon, air-fuel ratios of the stoichiometric and lean regions can be detected.
As this sensor is heated to a high constant temperature, it has sufficient accuracy without any additional temperature compensation. Its starting time is short and response time is very quick.
Citation: Suzuki, S., Sasayama, T., Miki, M., Yokono, H. et al., "Thick-Film Zirconia Air-Fuel Ratio Sensor with a Heater for Lean Mixture Control Systems," SAE Technical Paper 850379, 1985, https://doi.org/10.4271/850379. Download Citation