Patent ID: 8148691

Claim:
A method for calibrating a dual-beam non-dispersive infrared (“NDIR”) gas sensor having a sample chamber useful to detect a water vapor gas, comprising: obtaining a variant sensor components domain (“G 0 ”) of the NDIR gas sensor when there is no water vapor gas in the sample chamber; obtaining a physics measurement domain (“G”) of the NDIR gas sensor for a set of known concentrations of the water vapor gas in the sample chamber, the known concentrations being measurable quantities exceeding zero; using G to calculate a G 0i from a known concentration of water vapor in the sample chamber for each of a plurality of master calibration curves; and selecting one of the plurality of master calibration curves as a calibration curve for the NDIR gas sensor by choosing one of the plurality of master calibration curves with a lowest difference between its G 0i and the G 0 of the NDIR gas sensor as the calibration curve of the NDIR gas sensor.