To improve reliability of measurements of particle size distribution, performances and characteristics of three measuring methods, scanning electron microscope-image analysis (SEM-IA), electric resistance analysis (ERA) and centrifugal sedimentation analysis (CSA), are compared and discussed. In this study, polystyrene/polyviniltoluene (PS/PVT), monodisperse particles and alumina particles ranging from 0.5 to 5μm in diameter are used.
It is shown that the ERA's data on the particle size distribution agrees with the SEM-IA's within 5% in the average diameter and within 0.05μm in the standard deviation for the PS/PVT monodisperse particles, but the CSA's data significantly differ from those of the others. In the CSA, Stokes' condition for particle sedimentation is distinctly disturbed by a temperature rise due to high speed rotation of sample. A new technique is proposed and confirmed to be effective to reduce the disturbance.
In the measurement of alumina particles, the obtained data are incompatible each other among the three measuring methods, because amorphous particle shape and wide size distribution of alumina particles give inherent and different characteristics for the particle detections in the respective measuring methods.