| 摘要 |
PURPOSE:To realize effective utilization of Pt by providing a lead for connecting a measuring electrode with an external terminal on the other side of a solid electrolyte, employing Pt at a part of the lead touching a gas to be measured, and employing a specific mixture of Pt and Pd at the untouching part. CONSTITUTION:A substantially tubular solid electrolyte 1 comprises a test tube-like part 1a, an enlarged part 1b, and a constant diameter part 1c, sequentially from the forward end thereof. The test tube-like part 1a substantially corresponds to the sensor detecting part, the enlarged part 1b is held by the sensor housing through an insulator, and a lead 2 is connected with an external terminal at the constant diameter part 1c. The lead 2 extends from the rear end of the test tube-like part 1a through the enlarged part 1b to the constant diameter part 1c along the outer face of the electrolyte 1. The lead is composed of Pt at the enlarged part 1b and composed of a mixture material of Pd/Pt (1/3) at the constant diameter part 1c not touching a gas to be measured. This structure reduces the required quantity of precious Pt significantly. |
