Non -dispersion infrared ray gas sensor

The utility model relates to a non -dispersion infrared ray gas sensor belongs to gas sensor technical field. This sensor includes: infrared light source, multiple reflection air chamber, multichannelinfrared detector and treater. The light end that advances of multiple reflection air chamber is provided with first speculum, and the light -emitting end is provided with the second mirror, and theinfrared light that infrared light source produced gets into the air chamber through advancing the light end, on first speculum and the second mirror through multiple reflection after the light -emitting end -fire go out to multichannel infrared detector to give the treater with infrared spectrum signal output. Light beam in the air chamber reflects through the fixed speculum in both ends, and airchamber wall does not participate in measuring beam's reflection, so the optical distance stably, can not lead to equivalent optical distance to change with polluting along with the air chamber ages,and range and detectability