| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas sensor which prevents a drop in insulation between terminal metal fittings, corrosion of the terminal metal fittings or the like as caused by water drops attributed to dew condensation inside while maintaining air permeability in a gas sensor which has a filter with a closed vent hole fixed with a cylindrical insertion member. SOLUTION: In the gas sensor in the second embodiment, outside air is introduced inside through a vent hole 58 axially piercing a seal member 17 at the center part of the circular cross section thereof. A gas permeating a water repelling filter 62 disposed in the vent hole 58 is guided into a space 166e for buffer formed inside a second cylindrical insertion member 166 and then, into an internal space of an outer cylinder 16 passing through an internal vent hole 166c. Thus, water drops generated by the dew condensation of steam are accumulated in the space 166e for buffer thereby blocking the water drops from adhering to the terminal metal fittings 23 and 33, a heater terminal part 40 and the like arranged inside the gas sensor. |
