Patent ID: 8415626

Claim:
A Non-Dispersive Infrared (“NDIR”) gas sensor for detecting the presence of a chosen gas, comprising: a mechanical housing comprising: a can having at least one inner reflective surface, a first window and a second window formed in the can; a header housing affixed to the can; a sample chamber affixed to the can; and an electronics module contained within the can, said electronics module comprising: an infrared source that emits radiation when power is applied to it; a reference detector that produces a reference output; a signal detector that produces a signal output; and a microprocessor that receives the reference output and the signal output; wherein each of the reference detector and the signal detector have an identical narrow band pass filter with the same Center Wavelength (“CWL”), Full Width Half Maximum (FWHM) and transmittance efficiency at the CWL; and wherein the reference detector and the signal detector are mounted in the electronics module so that the at least one inner reflective surface and the sample chamber create a signal channel path length detected by the signal detector that is greater than a reference channel path length detected by the reference detector.