Buoyancy weighing-bar method: A particle size distribution measurement using a new settling method

Abstract

The buoyancy weighing-bar method is a new settling method of a particle size distribution measurement. Using this method, we measured the particle size distributions of the test powders standardized by Japanese Industrial Standards. The particle size distributions of the JIS Test Powders 1, class 4 (Talc), class 5 (Fly ash), class 8 (KANTO (Japanese) loam) measured using sodium pyrophosphate solution or ethanol as a dispersed liquid. The particle sizes of the JIS Test Powders 1, class 4 (Talc) and class 8 (KANTO (Japanese) loam) could be measured from 5 to 75μm in 2 h of measuring time. The particle size distribution of JIS Test Powders 1, class 4 (KANTO (Japanese) loam) measured by this method was close to those measured by the other settling methods and the laser diffraction/scattering method. However, the particle size distributions of the JIS Test Powders 1, class 4 (Talc) and the JIS Test Powders 2, No. 4 (White fused alumina) measured by this method were different from those measured by the laser diffraction/scattering method. There is no effect of the particle concentration on the particle size distribution when the particle concentrations of the JIS Test Powders 2, No. 4 (White fused alumina) are 10kg/m3 or less.