Calibration and correction of laser-induced incandescence for soot volume fraction measurements

A procedure for accurately calibrating and correcting the projected laser-induced incandescence (LII) intensity measurements for axisymmetric flames is presented. The corrected LII intensity and soot volume fractions along the measurement axis (which are unknowns) are calculated using the projected LII distribution. This technique does not require calibration using an independent measurement of soot volume fraction. Instead, a single line-of-sight extinction measurement is needed to obtain the calibration factor and corrections for the projected LII intensities. This technique is demonstrated to provide accurate soot concentrations for mediums producing significant trapping of the LII signal. (C) 1998 by The Combustion Institute.