Development of Planar Air Fuel Ratio Sensor

In preparation for compliance with California's SULEV standard and the Euro STAGE-4 standard, which will take effect in 2004 and 2005, respectively, a planar air fuel ratio (A/F) sensor has been developed. By using technology established for the planar oxygen sensor already in practical use, the A/F sensor realizes light-off time of 10 seconds, faster than any conventional A/F sensors. In addition, with its newly developed gas diffusion structure, the planar A/F sensor provides high detection accuracy for a wide A/F range, from rich to lean.