Apparatus and method for measuring particle size distribution by light scattering

摘要

Apparatus 200 for measuring the particle size distribution of a sample by light-scattering comprises focusing optic 202 for producing a converging beam 203 generally along a propagation axis z. The apparatus comprises a mounting system which allows a dry sample cell 208A and a wet sample cell 208B to be mounted in the converging beam at different times and in respective planes which are mutually inclined at angles α1, α2, so that in use respective positions 212, 214 at which transmitted light is focused for the two cells have a difference in displacement from the z axis r1, r3 that is less than for the case where the respective mounting planes are substantially parallel. This allows use of a cheaper and less complex translation stage within the apparatus for mounting an optical detector for locating the two focus positions.