Minimum deviation of spatial frequency in large-particle sizing

A new method is introduced to improve the accuracy of sizing large particles in two-phase flows. This method uses a photodetector array to measure directly the spatial frequency of the light intensity scattered from a spherical particle in the measurement volume (or cross-sectional area). The effects of both the reflected and the refracted rays are considered. The phase conversion factors from the refracted and the reflected rays are used to minimize the measurement volume effect (errors) in sizing large particles. Furthermore, optimization results are compared with the results from the simulation based on the generalized Lorenz-Mie theory. A new particle-sizing system that combines the conventional and the new methods is suggested. (C) 1998 Optical Society of America