Patent ID: 8535498

Claim:
A method for clamping an electrochemical gas sensor including: a disc-shaped metal bottom member; a cylindrical metal side member that extends in at least a first direction along an axial direction of the bottom member so as to surround the bottom member; a ring-shaped polymer gasket that includes an opening in the center and in which both sides of the opening each have an L-shaped member in cross section; a gas sensor body including at least a pair of electrodes and a solid electrolyte membrane or a separator retaining a liquid electrolyte; and a metal cover having a circular bottom surface, the cover including a ring-shaped protrusion provided around periphery of the cover and extending to a side opposite the bottom surface along the axial direction of the cover, the method comprising the steps of: disposing the gasket, the gas sensor body and the cover on the bottom member such that the one section of the L-shaped member of the gasket is surrounded by the side member and the other section is in contact with the bottom member, that the gas sensor body is located in the opening of the gasket and a bottom surface of the gas sensor body is in contact with the bottom member, and that the bottom surface of the cover covers a top surface of the gas sensor body and the ring-shaped protrusion of the cover extends to a side opposite the bottom member; and bringing a surface of a hole of a mold tapered to have a larger diameter at front and a smaller diameter at rear into contact with a tip end of the side member, whereby the tip end of the side member and a tip end of the one section of the L-shaped member of the gasket are bent at an acute angle toward the bottom member from the first direction, the tip end of the side member, the tip end of the one section of the L-shaped member of the gasket and a tip end of the protrusion of the cover are in hermetic contact with each other, and the three tip ends are clamped such that none of them is parallel to a surface of the bottom member.