Particle size measurement of standard reference particle candidates with improved size measurement devices

In order to prepare standard reference particles, experimental and theoretical studies have been conducted on particle size measurement of two kinds of spherical glass beads. The sheath flow- type electrical sensing zone method and the revised sedimentation balance method were used for the measurement. The data were compared with those obtained by the microscopic method with a sample size greater than 10 000. The particle size distributions obtained by use of the sheath flow- type electrical sensing zone method and microscopic method are nearly equal for the two kinds of glass beads. However, deviations of less than 5% were observed between the improved sedimentation balance and microscopic methods. The experimental data of the microscopic method are within the 95% reliability region of the sheath flow-type electrical sensing zone method.