Measurement of particle size in the dense suspension using the extinction method

All light scattering based instrumentation should be arranged and used under condition of the absence of multiple scattering. Using the extinction method, experimental studies have been performed to investigate the effect of multiple scattering on the measurement of size. Monodisperse polystyrene latex spheres and polydisperse industrial samples are used for size measurements at different particulate concentrations. However, experimental data show that even for the very dense suspensions, whose optical path tau L may be as large as 2.5-2.7 or the extinction I/I-o, as low as 0.06-0.07, the measured diameters agree well with the nominal values of the polystyrene latex spheres.