Particle Size Standard Materials (Transparent and Black)

Executive Summary

This year project of the spherical reference materials is to manufacture both transparent (LBP 150-650) and opaque (GCP 150-650) particles having unimodal size distribution in the range of 150 to 650pm.

1. The transparent particles are soda-lime-silicate glass beads denoted by LBP150-650, and more than 95% in weight of these particles are in the size range of 150 to 650pm. The product materials, LBP150-650, of 30kg were sent to the AEA Technology, England for the certification in December, 1993.
2. The opaque particles are glassy carbon beads denoted by GCPlSO- 650, and more than 95% in weight of these particles are in the size range of 150 to 650 pm. The product materials, GCP150-650, of 24kg were also sent to the AEA Technology, England in May, 1994.

The physical characteristics of the above product materials, especially the size distributions, were measured in several Japanese company-laboratories, and are given in this report.

We also studied the size segregation of larger particles in a vessel through tapping, resulting in a significant segregation. Therefore, complete mixing and/or careful splitting is necessary before utilizing them as the reference materials.

The next year project will be concerned with the following two problems relating the standard materials.

• to get additional important physical properties of the standard materials.
• to find a method for estimating the statistical error caused by the sample size utilized in a particle size measurement.