| 摘要 |
PURPOSE:To obtain an oxygen sensor for detecting the concentration of oxygen stably for a long term while sustaining diffusion of gas into a diffusion resistance layer. CONSTITUTION:The oxygen sensor comprises a sensor section 50 including electrodes 31, 32 disposed on the surface of a solid electrolyte 5, and a diffusion resistance layer 2 covering the sensor section 50. The surface of the diffusion resistance layer 2 is coated with a porous protective layer 1 containing a compound of phosphoric acid. The protective layer preferably carries P2O5, and Al2O3 simultaneously and contains 6.5-7.5 pts.wt. of Al2O3 for 1 pts.wt. of P2O5. The protective layer 1 preferably has porosity in the range of 20-50% and a catalyst carrying layer is interposed between the diffusion resistance layer 2 and the protective layer 1. |
