| 摘要 |
PURPOSE:To provide the manufacture of an oxygen sensor element which is uniform in its film thickness, capable of forming a bubbleless poisoning substance trapping layer, excellent in the poisoning substance trapping effect, and stable in the sensor characteristic. CONSTITUTION:The surface on the detection gas side of an oxygen detecting element is dipped into a slurry in which coarse heat-resistant metallic oxide particles of a mean grain diameter of 2 to 50mum are dispersed, and the slurry is attached on the surface of the protective layer of the oxygen sensor element, and thereafter, it is dried and baked, so that a porous poisoning substance trapping of a film thickness of 10 to 500mum is formed. The dipping is carried out after the slurry has been previously deaerated, strongly stirred, and the stirring has been stopped. The deaeration of the slurry is preferably carried out under a reduced pressure of less than 10kPa, and for at least 30 minutes. |
