| 摘要 |
PURPOSE:To obtain a sensor of linear and high sensibility and capable of detecting exactly an air fuel ratio in a wide range by forming porous electrodes on both surfaces of an oxygen ion conductive solid electrolyte, providing a porous electrode of measuring gas side with semicatalytic performance and incorporating a specified metallic oxide. CONSTITUTION:A paste of a metal such as Pt, Pd is applied to coat the both surfaces of the oxygen ion conductive solid electrolyte (ZrO2, etc. stabilized by Y2O3) 1 to form the porous electrodes 2, 3 which have not high catalytic activity of a degree oxidizable most of HC and CO to H2O and CO2 (called as semicatalytic ability). A layer of the metallic oxide 4 of >=1 kinds among SnO2, In2O3, NiO, CO3O4 and CuO and a mixed solution of ethyl silicate and alcohol are impregnated, dried and ignited to the electrode 3 contacting with the measuring gas 6. By locating the layer 4 near a three phase point of the electrode 3, the electrolyte 1 and the measuring gas, the air fuel ratio can be measured exactly from rich to lean regions. |
