A multispecies near-infrared diode laser spectrometer has been constructed for measurements of carbon monoxide, carbon dioxide, and methane directly in the exhaust of a static internal combustion engine. A wavelength modulation-division multiplexing scheme was implemented for the two distributed feedback diode lasers. Gas concentration variations were observed for changes in operating conditions such as increasing and decreasing the throttle, adjusting the air–fuel ratio, and engine start-up.
© 2007 Optical Society of America
Original Manuscript: October 16, 2006
Revised Manuscript: February 28, 2007
Manuscript Accepted: February 28, 2007
Published: June 12, 2007
Yvan Gérard, Robert J. Holdsworth, and Philip A. Martin, "Multispecies in situ monitoring of a static internal combustion engine by near-infrared diode laser sensors," Appl. Opt. 46, 3937-3945 (2007)