Chapter 7. Air-Fuel Ratio Sensors for Automotive Use Utilizing ZrO2 Electrolytes

  1. William Smothers
  1. Takao Sasayama,
  2. Seiko Suzuki,
  3. Minoru Ohsuga and
  4. Sadayasu Ueno

Published Online: 27 MAR 2008

DOI: 10.1002/9780470320419.ch7

14th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 8, Issue 9/10

14th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 8, Issue 9/10

How to Cite

Sasayama, T., Suzuki, S., Ohsuga, M. and Ueno, S. (1987) Air-Fuel Ratio Sensors for Automotive Use Utilizing ZrO2 Electrolytes, in 14th Automotive Materials Conference: Ceramic Engineering and Science Proceedings, Volume 8, Issue 9/10 (ed W. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320419.ch7

Author Information

  1. Hitachi, Ltd. Tokyo, Japan

Publication History

  1. Published Online: 27 MAR 2008
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780470374740

Online ISBN: 9780470320419

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Keywords:

  • atmospheric;
  • technology;
  • hydrocarbons;
  • platinum;
  • combustion

Summary

A new concept of the air-fuel ratio sensing method utilizing the oxygen ion transportation mechanism in the zirconia (ZrO2) solid electrolyte has been proposed. The sensing element was composed of zirconia with a pair of porous platinum electrodes; one of the electrodes is covered by a gas diffusion layer. The mechanism of ion transportation in this structure was analyzed under the assumption that the one side of the sensing element was exposed to an exhaust gas environment, and the other side was exposed to an atmospheric environment. It has been concluded that the electric current transferring through the electrodes can represent the air-fuel ratio proportionally, if the electromotive force across the electrodes is kept constant within several hundred mV. Several types of prototype sensors have been tested under the actual exhaust gas environments of automobiles and experimental results having good agreement with the theoretical analysis have been obtained.