OPTICAL TRAP SEDIMENTATION CELL-A NEW TECHNIQUE FOR THE SIZING OF MICRO PARTICLES

In this paper a new technique for the sizing of optically levitated particles is reported. It is based upon the analysis of the dynamical behavior of the investigated particle during a transient interruption of the supporting laser beam, A mathematical model to describe the movement of the particle was developed and experiments with various samples were performed. The evaporation of single- and two-component droplets were monitored on-line. To allow a verificahon of the obtained results. the intensity of the light scattered by the particle was recorded simultaneously during the experiments, Comparison of measured data and computations according to Lorenz··Mie theory showed that the reported technique enables the determination of particle size with an accuracy better than I % in less than 1 min without knowledge of its optical properties