Comparison of laser-induced incandescence method with scanning mobility particle sizer technique: The influence of probe sampling and laser heating on soot particle size distribution

We present a simple method for comparing particle size measurements, obtained with laser-induced incandescence (LII) and a scanning mobility particle sizer (SMPS) in a premixed laminar sooting flame. A quartz cell was installed in line with the SMPS probe to allow LII measurements within the SMPS sample line. In this configuration, the LII and SMPS measurements gave similar results in terms of mean particle size. After the probe, the soot particles appear to be made of tight compact particles. In addition, with this experimental configuration, the influence of the probe in the flame is studied for different particle size ranges by applying LII before and after the probe. Application of SMPS with and without LII in the quartz cell shows that laser heating during LII measurements has an influence on the soot particle size distribution. The method could be used to improve probe sampling of particulate matter in reactive fields as well as to validate the interpretation of relevant physical mechanisms involved in the LII process. © 2005 IOP Publishing Ltd.