Real-time trace-level detection of carbon dioxide and ethylene in car exhaust gases.
A direct-absorption spectrometer, based on a pulsed, distributed feedback, quantum cascade laser with a 10.26-microm wavelength and an astigmatic Herriott cell with a 66-m path length, has been developed for high-resolution IR spectroscopy. This spectrometer utilizes the intrapulse method, an example of sweep integration, in which the almost linear wavelength up-chirp obtained from a distributed feedback, quantum cascade laser yields a spectral microwindow of as many as 2.5 wave numbers/cm(-1). Within this spectral microwindow, molecular fingerprints can be monitored and recorded in real time. This system allows both the detection of carbon dioxide and ethylene and the real-time observation of the evolution of these gases in the exhaust by-products from several cars.
McCulloch
Michael T
MT
Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow, G4 ONG, United Kingdom.
Langford
Nigel
N
Duxbury
Geoffrey
G
D000393:Air Pollutants / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis*; D003199:Computer Systems; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005030:Ethylenes / Q000032:analysis*; D008832:Microchemistry / Q000379:methods*; D013055:Spectrophotometry, Infrared / Q000295:instrumentation / Q000379:methods*; D001335:Vehicle Emissions / Q000032:analysis*
D000393:Air Pollutants; D005030:Ethylenes; D001335:Vehicle Emissions; D002245:Carbon Dioxide; C036216:ethylene