A modified laser doppler technique for simultaneous determination of particle size and deposition velocity

Size determination by laser Doppler anemometry (LDA) is not possible with conventional techniques for small particles. However, using non-Gaussian modes in a 2D-LDA, information on the particle trajectory can be obtained so that particle size can be inferred from its scattered light amplitude, while deposition velocity is determined with the technique developed previously. Theoretical fundamentals of the method are presented together with details of the experimental setup as well as first results from field measurements.