PURPOSE: To accelerate the response speed of an oxygen sensor, in an oxygen sensor using a solid electrolyte, by using a composition, which contains platinum as a main component and added with rhodium and rare earth metal oxide, as the electrode material of said sensor.
CONSTITUTION: An oxygen sensor 1 is constituted so that a temp. holding heater 3 is embedded in an alumina substrate 2 and an intermediate layer 4 using an oxygen ion conductive solid electrolyte comprising stabilized zirconia, a first electrode and an oxygen ion conductive solid electrolyte 6, a second electrode 7 are successively laminated onto the substrate 2 and the entire surface is covered with a porous protective layer 8. Herein, the first electrode 5 is formed of, for example, a Pt-19% Rh paste and the second electrode is formed of a paste comprising a conductive material based on platinum and containing 1W 30wt% of rhodium and rare earth metal oxide containing Y. By using this electrode material, a rising and falling response speed can be accelerated without changing an output attenuation time constant.
ISHITANI MASAO
KIMURA SHINJI
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