Double puise technique for the evaluation of the saturation parameter in single-shot laser induced fluorescence measurements: an application to lead in a flame

摘要

The enlargement of the piobe volume in saturated laser induced fluorescence measurement is a considerable drawback for absolute concentration measurements. For practical purposes, a double pulse technique was developed allowing determination of the saturation parameter, which has a major influence on the probe volume enlargement. The technique is based on the detection of the fluorescence produced by two time-delayed laser pulses of different intensity. The basic theory of the technique is presented,together with the results of an experimental application to Pb in an acetylene/air flame. The implications for absolute concentration measurements are also discussed.