The detection limits for NO and NO2 in turbine exhausts by nonintrusive monitoring have to be improved. Multipass mode Fourier-transform infrared (FTIR) absorption spectrometry and use of a White mirror system were found from a sensitivity study with spectra simulations in the mid-infrared to be essential for the retrieval of NO2 abundances. A new White mirror system with a parallel infrared beam was developed and tested successfully with a commercial FTIR spectrometer in different turbine test beds. The minimum detection limits for a typical turbine plume of 50 cm in diameter are approximately 6 parts per million (ppm) for NO and 9 ppm for NO2 (as well 100 ppm for CO2 and 4 ppm for CO).
© 2005 Optical Society of America
(280.1120) Remote sensing and sensors : Air pollution monitoring
(280.1740) Remote sensing and sensors : Combustion diagnostics
(300.1030) Spectroscopy : Absorption
(300.2140) Spectroscopy : Emission
(300.6340) Spectroscopy : Spectroscopy, infrared
Klaus Schäfer, Klaus Brockmann, Jörg Heland, Peter Wiesen, Carsten Jahn, and Olivier Legras, "Multipass open-path Fourier-transform infrared measurements for nonintrusive monitoring of gas turbine exhaust composition," Appl. Opt. 44, 2189-2201 (2005)