EXPERIMENTAL ASSESSMENT OF O-2 INTERFERENCES ON LASER-INDUCED FLUORESCENCE MEASUREMENTS OF NO IN HIGH-PRESSURE, LEAN PREMIXED FLAMES BY USEOF NARROW-BAND AND BROAD-BAND DETECTION

We experimentally investigate the influence of O-2 interferences on la ser-induced fluorescence measurements of NO in lean methane-fueled fla mes at a range of pressures for both narrow-band and broadband fluores cence detection. We identify NO excitation schemes that minimize O-2 i nterferences. From detection scans we obtain interference spectra for the different NO excitation schemes. We then identify optimum excitati on-detection schemes for narrow-band detection measurements of NO. To simulate broadband detection experiments, we numerically apply five di fferent filter combinations to the experimentally obtained detection s cans. We develop filter-assessment parameters to judge the effectivene ss of the different filtering schemes, and we establish a methodology for evaluating broadband excitation-detection strategies. From this re search we identify optimum excitation-detection schemes for broadband detection measurements of NO. (C) 1996 Optical Society of America