Dual-pump CARS measurements of N2, H2 and CO in a partially premixed flame

• Published in: Journal of Raman spectroscopy Vol. 38; no. 8; pp. 983 - 988
• Main Authors: Weikl, Markus C., Seeger, Thomas, Hierold, Ruth, Leipertz, Alfred
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2007
• Subjects: Carbon monoxide; CARS; Coherent scattering; combustion diagnostics; concentration measurements; Diffusion; hydrogen; Mathematical analysis; Premixed flames; Raman scattering; Spectra; temperature measurements
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.1700

A three‐laser, dual‐pump coherent anti‐Stokes Raman scattering (CARS) technique for the simultaneous detection of nitrogen, carbon monoxide and hydrogen has been developed and tested. Hydrogen Q‐branch lines were used for the determination of relative hydrogen concentrations, which offers a much wider range of detectivity in contrast to approaches in which S‐branch transitions are used. Consequently, hydrogen concentrations could be measured over a whole range of temperatures, from room air to a flame. Measurements were taken in a heated cell and in a partially premixed propane/air flame. Measurements in the cell were in good agreement with theoretical spectral calculations. From measurements in the flame, the relative concentrations of hydrogen and carbon monoxide, which were generated as intermediate species, could be determined. Furthermore, diffusion effects of hydrogen could be observed with the presented approach. Copyright © 2007 John Wiley & Sons, Ltd.