| 摘要 |
PROBLEM TO BE SOLVED: To provide an oxygen sensor which prevents an electrode from being poisoned by lead even in a low-temperature combustion gas, whose responsiveness and durability are stable for a long period and whose peeling resistance is superior, and to provide its manufacturing method. SOLUTION: This oxygen sensor is provided with a sensor element wherein an oxygen-ion-conductive solid electrolyte body 1, an inside electrode 3 which is arranged and installed on the inner surface of the solid electrolyte body, an outside electrode 2 which is arranged and installed on the outer surface of the solid electrolyte body so as to form a pair with the inside electrode, an electrode protective layer 4 which covers the outside electrode, and a lead- poisoning preventive layer 5 which covers the electrode protective layer. The lead-poisoning preventive layer is composed of a titanium oxide powder whose specific surface area is at 1 to 20 m2/g. The porosity of the lead-poisoning preventive layer is at 40 to 80%, and its thickness is at 20 to 200 μm. The electrode protective layer 4 has a thickness of 150 to 300 μm. |
