Patent ID: 6360581
Filing Date: 2002-03-26
Classification: G01N

Abstract:
A gas sensor comprising:a sensing element having a sensing portion formed at a tip end portion thereof and adapted to detect a component of a gas under measurement; and a cylindrical casing covering the sensing element while the gas under measurement is permitted to flow therethrough to the sensing portion; said casing including at least one inner cylindrical member and at least one outer axially adjacent cylindrical member; an end portion of the one inner cylindrical member disposed within a corresponding end portion of the one outer cylindrical member to thereby form an overlap zone; a circumferential diameter-reduced portion formed on the outer member in such a manner as to be located at an axially intermediate position of the overlap zone; and a weld zone circumferentially formed at the diameter-reduced portion so as to establish an airtight bond between the outer member and the inner member.