| 摘要 |
PURPOSE:To stabilize a gas detection element over long period of time, by using a filter, wherein a metal copper film is formed to an activated alumina main body, as the filter for removing the substance obstructing the detection capacity of a gas sensor. CONSTITUTION:A cap shaped filter 6 is provided to the upper part of a gas detection element and a gas sensor 3, a coil heater 4 and an explosion-proof net 5 are arranged in said filter 6 while an electrode pins 1 are connected to the gas sensor 3. The filter 6 is formed by providing a metal copper film to the main body of porous activated alumina by sputtering. Activated alumina has effect for adsorbing and removing SO2 and metal copper has effect for adsorbing and removing H2S. Because the filter prepared by forming the metal copper layer to the activated alumina main body is used as a filter, the substance obstructing detection capacity is removed and the gas detection can be made stable and highly reliable over a long period of time. |
