| 摘要 |
PURPOSE:To suppress the hysteresis and deterioration caused by a reducing atmosphere of a high temp. and to improve the accuracy of detection in an exhaust gas sensor which utilizes the change of the resistance value of a metallic oxide semiconductor by using a specific material for said semiconductor. CONSTITUTION:A whisker 2 of SnO2 is cut and noble metals 4, 6 are thermally sprayed to both ends of the whisker 2. Noble metal lead wires 8, 10 are attached thereto. Such whisker is contained into the recesses 14, 16, 18 in an alumina substrate 12 and the lead wires 8, 10 are fixed by inorg. adhesive agents 20, 22 near the inlets of the recesses 16, 18 to suspend whisker 2 in the recess 14. On the other hand, external leads 24, 26 are connected to the other ends of the lead wires 8, 10. The other parts of the whisker 2 except the periphery thereof are laminated with an alumina film to shut off the lead wires 8, 10 from the atmosphere. The compsn. of the waste gas is detected from the change of the resistance value of the metallic oxide SnO2 semiconductor. The deterioration is suppressed by using the whisker-like SnO2, by which the accuracy of detection is improved. |
