| 摘要 |
PURPOSE:To form a sensor housing into thorough waterproof construction and to prevent the generation of defective insulation by constituting the titled device in such a manner that reference oxygen is supplied by an oxygen pump effect to an electrode to be provided in an oxygen sensor element and to be brought into a reference gas. CONSTITUTION:An oxygen detecting part 4 is formed to the top end of the oxygen sensor element 2 and the prescribed signal obtd. based on the principle of an oxygen concn. cell is taken out of the base end of the element 2. The element 2 is housed in a protective tubular body 12 in a manner that the oxygen detecting part 4 at the top end side thereof is substantially airtightly isolated from the base end side thereof by sealing layers 14, 16. On the other hand, plural gas introducing holes 32 are formed at the top end of the protective tubular body 12. Since the element 2 is airtightly attached to a partition wall 38, the gas to be measured in a flow passage for the gas to be measured is conducted through the gas introducing holes 32 into the oxygen detecting part 4 of the element 2. The protective tubular body 12 is not provided with holes communicating with the atm in the above-mentioned manner and therefore, the protective tubular body 12 is airtightly sealed by a rubber plug 26 on the base end side and the intrusion of water, salt water, mud water, etc. into the protective tubular body is obviated. |
