Patent ID: 8097856
Filing Date: 2012-01-17
Classification: G01N

Abstract:
1. A Non-Dispersive Infrared (“NDIR”) gas sensor for detecting the presence of a chosen gas, comprising: a single infrared source for generating infrared radiation; a sample chamber having a signal channel path length and a reference channel path length, the signal channel path length being greater than the reference path length; electronics for determining a sample concentration of the chosen gas; a single detector package, comprising: a reference light tunnel for funneling infrared radiation from the reference channel path length onto the reference detector; and a signal light tunnel for funneling infrared radiation from the signal channel path length onto the signal detector; wherein the reference light tunnel is physically separate from the signal light tunnel so that infrared radiation traveling through either the reference light tunnel or the signal light tunnel will not pass into the other tunnel as it is traveling through its own tunnel; wherein the signal channel path length is sufficiently greater than the reference channel path length so that the electronics can use an absorption bias between the signal output and the reference output to determine the chosen gas concentration in the sample chamber by using the reference output and the signal output obtained solely from use of the single infrared source; and wherein the single infrared source is the only source of infrared radiation emitted into the sample chamber.