GAS DETECTION ELEMENT WITH FILTER

摘要

PURPOSE:To stabilize a gas detection element over a long period of time, by using a filter equipped with an activated alumina layer and a zinc oxide layer as the filter for removing the substance obstructing the detection substance of a gas sensor. CONSTITUTION:A pipe 6 comprising Pyrex glass is adhered to the substrate 3 of a gas detection element and a filter 7 is provided to the upper opening part of the pipe 6 while a gas sensor 3, a heater 4 and an explosion-proof net 5 are arranged in the pipe 6 and electrode pins 3 are connected to the gas sensor 3. The filter 7 is constituted by laminating a glass filter layer 8, an activated alumina layer 9 and an activated zinc oxide layer 10. Activated alumina has effect for adsorbing and removing SO2 and activated zinc oxide has effect for adsorbing and removing H2S. Because the activated alumina and activated zinc oxide filter layers are provided as a filter, the substance obstructing detection capacity is removed and the gas detection element can be made stable and highly reliable over a long period of time.