Sedimentation image analysis (SIA) for the simultaneous determination of particle mass density and particle size

A new method for the simultaneous determination of the distribution of part icle mass density and the distribution of particle size with a technique wi th only a single measurement is presented. The basic idea of the new optica l method is the analysis of gravitational particle settling by a digital im age acquisition system. Individual particles illuminated by a laser light s heet are tracked by a continuously operating CCD camera. The projected area , shape factors and the centre of gravity are detected during the sedimenta tion process from a series of images with a constant time spread. As the al gorithm is based on single particle tracking, the heterogeneity of the samp le can be taken into account. From these measured particle characteristics, particle size and settling rate are calculated. Thus particle mass density is obtained taking into account also the influence of particle shape on th e settling process. This method, which we name sedimentation image analysis (SIA), is particularly suitable for the characterization of heterogeneous material, e.g. soil, in the micrometer range.