| 摘要 |
PROBLEM TO BE SOLVED: To realize a gas sensor capable of performing a highly accurate air- fuel control by preventing deviations in the output of the sensor due to H2 contained in exhaust gases from a natural gas engine and greatly improving the detection accuracy and further capable faster starting air-fuel ratio control by shortening the activating time of the sensor. SOLUTION: An inside electrode 22 is provided on the inner surface of a test tube-shaped oxygen-ion conductive solid electrolyte 21, and an outside electrode 23 is provided on the outer surface. A porous protective coating 24 to cover the surface of the outside electrode 23 exposed to exhaust gases is provided, and a catalyst layer 5 with an oxidizing action is further formed on the surface of the protective coating 24 to remove H2 contained in exhaust gases by an oxidizing reaction. By letting the catalyst's carrying amount be 0.5-2 wt.% with respect to the total weight of the catalyst layer 5, it is possible to prevent deviations in the output of the sensor without reducing responsivity. |
