| 摘要 |
PURPOSE:To obtain superior heat resistance and fast response and to take measurements over a wide range from a lean area to a rich area by covering an electrode outside a solid-state electrolyte element with a gas diffusion layer consisting of porous electric insulating metal oxide. CONSTITUTION:Porous thin-film electrodes 2a and 2b are provided on the internal and external surfaces of the solid-state electrolyte element made of oxygen ion conductive metal oxide and the electrode 2b outside the solid-state electrolyte element 1 is covered with the gas diffusion layer 3 consisting of the porous electric insulating metal oxide, and a constant voltage is applied between both electrodes 2a and 2b to ionize the oxygen in the atmosphere where the solid- state electrolyte element 1 is placed and also diffuse it in the solid-state electrolyte element. Further, the gas diffusion layer 3 which covers the entire surface of at least the external electrode 2b is formed of an extremely fine particle coating of porous magnesia spinel. Consequently, the heat resistance and response are superior and the air fuel ratio is measured over the wide range from the lean area to the rich area. |
