Patent ID: 6107631
Filing Date: 2000-08-22
Classification: G01N

Abstract:
In a spectral absorption system for determining the concentration of a particular gas in a gaseous sample using a sensor to sense a characteristic narrow spectral pulse in the absorption characteristics of the sample the area of which is proportional to the concentration of the particular gas, a method of on-line recalibration of the system to compensate for time or usage induced degradation in system accuracy without introducing a sample of a known concentration of the gas into the system comprising;storing information relating to a prior sensor response and a known gas concentration;combining a stored sensor response to a particular known gas concentration with a present sensor response to simulate a present sensor response to said known particular gas concentration, in the presence of an imprecisely known concentration of the particular known gas; andupdating the stored information to provide information relating the present sensor response and the particular known gas concentration.