| 摘要 |
PURPOSE:To obviate the failure of a sensor package even if a built-in heater is heated by forming a plate-shaped insulating layer in such a manner that the thickness size from the heater to a zirconia layer and the size from the heater to the outside surface of the insulating layer are approximately equal to each other. CONSTITUTION:A diffusion chamber 12 is formed in the plate-shaped zirconia layer 11 as an oxygen ion conductive solid electrolyte. A reference electrode 13 is disposed to the outside surface in the wall part 11a of the layer 11 and a measuring electrode 14 is disposed to the upper wall of the chamber 12. The insulating layer 15 embedded therein with the heater 16 is joined to the bottom surface of the layer 11. The layer 15 is so formed that the boundary thickness 15a from the heater 16 up to the layer 11, the thickness 15b down to the bottom wall surface and the distance 15l up to the side wall are equidistant. The layer 11 is heated by the heater 16 of the bottom surface. An oxygen-contg. gas to be measured contacts the electrode 13 and contacts the electrode 14 through the chamber 12 when such oxygen sensor is disposed into said gas. The gas passes both electrodes 13, 14 and a diffused into the layer 11, thus generating the pump current corresponding thereto. The current value is detected with both electrodes 13, 14, by which the oxygen concn. is detected. |
