Particle Size Analysis of a Mixed Sample of Three Sizes with Equal Log Spacing

Certified National Institute of Standards and Technology (NIST) traceable polystyrene latex (PSL) size standards made by Thermo Fisher Scientific Inc. (TFS) were used to evaluate the resolution of the centrifugal sedimentation method. Mean diameters of the PSL standards have been calibrated with microscopy methods. Size distribution and uniformity were measured with electrical resistance analysis or optical microscopy.  Fig. 1 shows the photograph of PSL particles. They have excellent roundness with a full particle size distribution. A mixed sample of three sizes with log-equal spacing, tri-modal picket fence that was made for the ISO TC24/SC4 WG11 evaluation was measured.