Patent ID: 8866085
Filing Date: 2014-10-21
Classification: G01N

Abstract:
1. A process for determining a sample concentration of a chosen gas in a single beam Non-Dispersive Infrared (“NDIR”) gas sensor, comprising: emitting infrared radiation from a single infrared source into a sample chamber that is alternatively pulsed at a high temperature and at a low temperature; detecting infrared radiation that is alternatively pulsed at the high temperature and at the low temperature by a detector after it passes through a narrow band pass filter with a spectral characteristic that substantially overlaps a strong absorption band for the chosen gas; and determining the sample concentration of the chosen gas by use of an absorption bias between a signal output of the detector at the high temperature and a reference output of the detector at the low temperature; wherein a convoluted output of the single infrared source and the narrow band pass filter is substantially coincident with the strong absorption band.