RESONANT OPTOACOUSTIC DETECTOR IN NONDISPERSIVE GAS ANALYZER SCHEME

A nondispersive gas analyzer scheme is suggested, in which the resonan t optoacoustic device is used for detection of air sample absorption, where modulation with the appropriate spectral filtration is carried o ut with the help of pure detecting gas cells. Analyzer performance for CO2, CO, CH4, SO2 and NO is studied. The modulation depth for gas cel ls was found to be between 0.45 for NO and 0.84 for CO2. Trace-gas det ectivity is limited by acoustical noise, originating from light beam c hopper at a level of 10(-2)%. Information about the influence of spect ral interference on detection selectivity was obtained: (C) 1997 Elsev ier Science B.V.