| 摘要 |
PURPOSE:To suppress the sensitivity with miscellaneous gases such as alcohol and to maintain such characteristic stably for a long period of time even under severe conditions such as in a reducing atmosphere of high temp. and high humidity and poisoning atmosphere by coating a porous layer consisting of at least one kind among composite oxides of Cu, Co, Mn, Ni, Fe and alumina on an outside layer. CONSTITUTION:A platnium film heater 2 is provided to the bottom surface of an alumina substrate 1 and the surface thereof is coated with a heater protective film 3. A platinum film electrode 4 is provided atop the substrate 1 and the surface thereof is coated with an SnO2 sintered layer 5 to constitute a gas detecting element of a thick film type consisting of a metallic oxide semiconductor. A porous layer consisting of at least one kind among composite oxides of Cu, Co, Mn, Ni, Fe and alumina is coated on the outside layer of the element. The sensitivity with the miscellaneous gases such as alcohol is thus suppressed and the cause for false alarm of a household gas leak alarm, etc. is eliminated. |
