| 摘要 |
PURPOSE:To obtain data of high reliability by supporting fine particles of a platinum group oxidation catalyst into the pores of a melt-sprayed ceramic protecting layer covering a transition metallic oxide layer, and burning the unburnt fuel in sample gas. CONSTITUTION:In an oxygen sensor provided with a transition metallic oxide layer (e.g.; a titanium dioxide layer) 4, metallic electrodes 2, 3 in contact with this layer, and a melt-sprayed ceramic protecting layer 5 covering the layer 4 on a ceramic base material 1, fine particles of a platinum group oxidation catalyst are supported in the pores of the protecting layer 5. Then, the sample gas such as the exhaust gas of automobiles contacts the catalyst in the fine pores of the layer 5 and is oxidized and removed of unburnt fuel nearly completely, after which it arrives at the layer 4, where it changes the resistance of the layer 4. This change is detected through the metallic electrodes 2, 3, and the accurate oxygen partial pressure of the sample gas is detected. |
