In general particle size analyzers, particles of the same size are measured as the same size regardless of material, making it difficult to separate particles of different materials when they are mixed together. The centrifugal sedimentation particle size analyzer measures the sedimentation speed and converts it into a particle size value using the density information of the particles. Therefore, particles of the same size but with different densities will have different settling speed and can be measured separately.
Polystyrene latex (PSL) and silica, both of which are used as NIST-traceable 1 μm standard particles, were mixed and measured on a Partica CENTRIFUGE centrifugal nanoparticle analyzer. Since the creation of a particle size distribution (PSD) requires calculations at one density, calculations were performed at each density of PSL and silica.