To obtain a gas sensor which is hard to clog by a method wherein a composite plated film which contains fine particles of a fluorine-based material so as to be dispersed is executed to the surface of a mesh used for a sensor cover.
Fine particles (in a mean particle size of 2 μm or lower) of a fluorine-based material such as graphite fluoride, fluororesin, pitch fluoride or the like are electrolyzed and precipitated on the surface of a meshlike material together with a metal, and a composite plated film is formed. A sensor element part is covered with a sensor cover which is obtained and whose stickness-resistant property, oil repellent property, durability and the like are excellent. As a composite plating liquid, a plating liquid which contains nickel, copper, chromium and the like can be used. A surface-active agent is used in order to disperse a fluorine compound uniformly. As the meshlike material, metals such as copper, stainless steel or the like, an ABS resin or other resins are used. In addition, after its composite plated film is formed, it is preferable that the film is heat-treated at 150 to 350°C for 30 minutes.
MORIYA KOJI
SAITO MICHIO
