| 摘要 |
PROBLEM TO BE SOLVED: To obtain an economical heater one-piece type oxygen sensor that relieves thermal stress caused by the difference of a thermal expansion coefficient, prevents an insulation layer from being easily released even when a sudden temperature cycle is added, and also can be manufactured at extremely low costs. SOLUTION: On the external surface of an oxygen sensor 1 where reference and measurement electrodes 3 and 4 are formed at opposing positions on the internal and external surfaces of a cylinder pipe 2 that is made of zirconia solid electrolyte and whose one end is sealed, a nonionic conductive porous insulation layer 5 such as spinel and a porous zirconia layer 6 are successively laminated, an electrical heating element 7 made of platinum is buried in the porous insulation layer 5 or between the insulation layer 5 and the zirconia layer 6, and at the same time the thickness of the porous insulation layer 5 from the electrical heating element 7 to the measurement electrode 4 is set to 1 to 100 μm. |
