In situ laser optical particle sizing

The fragile nature of natural suspended particle aggregates and the consequent need for non-destructive methods of analysing their size distribution are reviewed. The advantages and limitations of laser diffraction apparatus and the performance of an in situ diffraction instrument are discussed in relation to an intercalibration exercise on the Elbe estuary. The potential for sizing fragile aggregates in highly turbid estuarine environments using a novel optical back scattering technique which overcomes many of the problems of laser diffraction, optical beam and optical imaging systems is considered.