DETECTION OF BENZENE AND OTHER GASES WITH AN OPEN-PATH, STATIC FOURIER-TRANSFORM UV SPECTROMETER

Releases of benzene and other gases have been detected and quantified using a novel optical, open-path instrument based on a deuterium light source and a static Fourier-transform spectrometer, The spectrometer uses Wollaston prisms to form an interferogram in the spatial domain t hat is recorded by use of a detector array. The instrument is designed to operate in the ultraviolet region of the spectrum between 200 and 270 nm, which coincides with strong absorption features in the spectra of many gases of environmental and health interest. Using the instrum ent with a 5-s measurement period provides a path-integrated concentra tion sensitivity to benzene of 2 parts in 10(6) times meter, which cor responds to a 20-parts in 10(9) detection limit over a typical path le ngth of 100 m. (C) 1998 Optical Society of America.