Patent ID: 8358417

Claim:
An analytical system comprising: a validation cell positioned such that light generated by a light source passes through the validation cell at least once in transmission of the light from the light source to a detector, the validation cell containing a reference gas comprising a known amount of an analyte compound, the light source emitting the light in a wavelength range that comprises a spectral absorbance feature of the analyte compound; and a controller to perform an instrument validation process and a sample analysis process, the instrument validation process comprising: receiving first light intensity data that quantify a first intensity of the light received at the detector while the light passes at least once through each of the reference gas in the validation cell and a zero gas having at least one of known and negligible first light absorbance characteristics that overlap second light absorbance characteristics of the analyte compound within the wavelength range, and verifying a valid state of the analytical system by determining that the first light intensity data do not deviate from a stored data set that by greater than a pre-defined threshold deviation, the stored data set representing at least one previous measurement collected during a previous instrument validation process performed on the analytical system; and the sample analysis process comprising: receiving second light intensity data that quantify a second intensity of the light received at the detector while the light passes at least once through each of the reference gas in the validation cell and a sample gas containing an unknown concentration of the analyte compound, and determining a concentration of the analyte compound in the sample gas by correcting the second light intensity data to account for a known absorbance of the light in the validation cell.