Abstract: A gas sensor including a gas sensor body in which is centrally inserted a gas detecting element and which permits the gas sensor itself to be attached to other members; a protective sleeve attached to an end portion of the gas sensor body; a seal member formed of a heat-resistant synthetic resin, the seal member being disposed inside an end portion on a lead wire draw-out side of the protective sleeve, with a lead wire extending through the seal member; and a spring member mounted within the protective sleeve for urging the seal member liquid-tightly against the lead wire draw-out side end portion of the protective sleeve. Since the seal member disposed in an end portion of the protective sleeve is formed of a heat-resistant synthetic resin, the durability thereof is improved even where high temperature gases such as the exhaust gases of internal combustion engines or the like are to be detected.

Abstract: The oxygen sensor for exhaust gas of internal combustion engine includes a solid electrolyte tube having an inner electrode coated on the inner surface of said electrolyte tube outer electrode formed on outer surface of said electrolyte tube and disposed on the outside surface thereof so as to come in contact with exhaust gas and a metallic protective tube coaxially surrounding said electrode with a spacing therefrom. The sidewall of the protective tube has two similarly arranged matrices of holes, each hole being made by cutting an arcuate edge on the sidewall and bending the thus cut portion toward the inside of the protective tube, and the holes of one matrix are interposed among the holes of the other matrix while being offset therefrom in both the longitudinal and circumferential directions of the protective tube.

Abstract: A heater-incorporating oxygen sensor includes a solid electrolyte oxygen sensor element comprising a solid electrolyte provided with electrodes on both its sides and a heater, said heater being a ceramic heater formed by sintering and embedding a metallized pattern in a ceramic insulator as one solid body, said ceramic heater being disposed within a space surrounded with said oxygen sensor element.