초록 ▼

A gas sensor including coating layers (64) and (69) of fluorine or a fluorine compound formed on the surface of a separator (60), including a front separator (61) and a rear separator (66), disposed inside a sheath (30). The coating layers (64) and (69) have water impermeability and water repellency

A gas sensor including coating layers (64) and (69) of fluorine or a fluorine compound formed on the surface of a separator (60), including a front separator (61) and a rear separator (66), disposed inside a sheath (30). The coating layers (64) and (69) have water impermeability and water repellency. Even in the case where moisture contained in the atmosphere within a sheath (30) forms dew on the surface of the separator (60), the coating layers (64) and (69) prevent soaking of moisture into the separator (60), to thereby secure the insulation property of the separator (60). Also, the coating layers (64) and (69) having water repellency prevent a water droplet from spreading on the surface of the separator (60) with resultant formation of a film of water, to thereby prevent flow of leakage current via a film of water.

대표청구항 ▼

1. A gas sensor comprising: a detection element extending in an axial direction and adapted to detect the concentration of a specific gas;a metallic shell circumferentially surrounding and holding the detection element;a sheath attached to a rear end portion of the metallic shell and surrounding a r

1. A gas sensor comprising: a detection element extending in an axial direction and adapted to detect the concentration of a specific gas;a metallic shell circumferentially surrounding and holding the detection element;a sheath attached to a rear end portion of the metallic shell and surrounding a rear end portion of the detection element; anda separator formed of an electrically insulating ceramic, disposed inside the sheath, and accommodating at least a plurality of conduction members for electrical connection with the detection element,the gas sensor being characterized in that a coating layer having water impermeability is directly formed on a surface of the separator. 2. The gas sensor according to claim 1, wherein the coating layer has water repellency. 3. The gas sensor according to claim 1, wherein the coating layer is formed of glass. 4. The gas sensor according to claim 1, wherein the detection element includes electrode pads formed on a rear end portion thereof for electrical connection with the conduction members;the separator further accommodates the rear end portion of the detection element; andthe electrical connection between the conduction members and the electrode pads is established inside the separator. 5. The gas sensor according to claim 1, wherein the coating is formed of a fluorine compound.