Frequency-domain photon migration techniques for online measurement of particle size distribution and volume fraction in concentrated process streams

摘要

Abstract: Frequency-domain measurements of photon migration were conducted in concentrated polystyrene suspensions in order to assess their use for on-line particle sizing in undiluted process streams. Using a numerical inverse algorithm, particle size distributions (PSD) and volume fractions of three latex suspensions with differing size distributions were recovered from phase-shift measurements at fifteen or less visible wavelengths. Comparison to dynamic light scattering measurements show excellent agreement. Since it is the propagation characteristics of multiply scattered light instead of the amount of light detected that is employed to solve the inverse problem, the measurement technique provides a self-calibrating (and therefore especially suitable) method for on-line process monitoring of PSD in the chemical-based industries. !16