Patent ID: 7754491

Claim:
A method of monitoring a component of a gas, comprising: a) transferring a first sample of a gas to a catalytic compartment of a gas sensor assembly; b) in the catalytic compartment, catalyzing a chemical reaction involving a component of the gas, whereby one or more gas species is produced; c) transferring some or all the one or more gas species to a product compartment of the gas sensor assembly; d) in the product compartment, sensing the amount of at least one gas species produced by catalysis; e) transferring a second sample of the gas to a reference compartment of the gas sensor assembly; f) in the reference compartment, sensing the amount of the same gas species as sensed in step (d); and g) determining a difference between the amount of the gas species produced by catalysis in step (d) to the amount of the same gas species in the second sample of the gas in step (f), thereby providing a measure of the amount of the gas component contained in the gas before catalysis, based on said difference and stoichiometry of said chemical reaction.