Patent ID: 7022992

Claim:
An apparatus for monitoring the flue gases of a furnace combustion process comprising, in combination: a by-pass circuit constructed and arranged to communicate a sample of flue gases to be monitored through a measurement chamber and through a return duct; the by-pass circuit having a gas sampling probe having a fume inlet opening, the probe being positioned for withdrawing the sample to be monitored and transmitting it through the by-pass circuit; a measurement device positioned in the measurement chamber and comprising an in situ optical device constructed and arranged to facilitate real-time measurement of targeted flue gas species concentrations, the targeted species including at least one of O 2 , CO, CO 2 , H 2 O, and H 2 , the measurement device further comprising an optical signal processor constructed and arranged to report a measured concentration to a controller that is constructed and arranged to control a process variable in relation to the measured concentration to optimize the process; and a vacuum drawing system constructed and arranged to draw the furnace flue gas to be monitored through the by-pass circuit.