| 摘要 |
PROBLEM TO BE SOLVED: To simply test the air tightness of oxygen sensor by providing on the midway of a lead wire a seal rubber as an auxilliary part for air tightness test. SOLUTION: A seal rubber 22 is provided between a seal member 21 and a connector 20, on lead wires 17 and 19 extending from a casing 2 for an oxygen sensor 1. When the casing 2 is subject to air tightness test, the seal rubber 22 is fitted to a fitting hole 28 of a container 27 for air tightness test, and the casing 2 and connector 20 are arranged inside and outside the container 27 respectively. In this state, the inside of the container 27 is pressurized by an air pump 31, and when sealing of the casing 2 is insufficient, the air pressure entering its inside leaks to the outside of the container 27 through the lead wires 17 and 19 and a drop of pressure is detected by a manometer 32. |
