| 摘要 |
PURPOSE:To enable measurement of both lean and rich regions by laminating a cathode, a porous oxygen ion conductive solid electrolyte film, an anode, and a porous protective film in this order on an insulating base plate, impressing constant potential between the cathode and the anode and measuring limiting diffusion current. CONSTITUTION:The cathode 2, the porous oxygen ion conductive solid electrolyte film 3 of ZrO2, etc., the anode 4, and a porous protective film 8 of ceramics, etc. are laminated in this order on an insulating base plate 1, thereby manufacturing an air-fuel ratio meter for automobiles which impresses constant potential between the electrodes 2 and 4 from a constant voltage power source 5 and measures limiting diffusion current with an ammeter 6. The cathode 2 and the anode 3 are formed respectively of thick films of porous platinum electrodes. The film 3 is formed of ZrO2 stabilized with Y2O3 and the protective film is formed by melt spraying of ceramics such as magnesia spinnel. The electrolytic current changes continuously in the rich and lean regions of the air-fuel ratio in the above-mentioned way and therefore the decision of the air-fuel ratio from the varying magnitude in the current value is made possible. |
