ASTM D 1155 - 03 Standard Test Method for Roundness of Glass Spheres

American Society for Testing and Materials (ASTM). Current edition approved May 10, 2003. Published June 2003. Originally approved in 1951. Withdrawn December 2002 and reinstated as D 1155 – 03. 3 p. This test method covers the determination of the percent of true spheres in glass spheres used for retroreflective marking purposes and industrial uses.
This test method includes two procedures as follows:
Procedure A, in which the selected specimen is split into two size ranges or groups prior to separation into true spheres and irregular particles, and
Procedure B, in which the selected specimen is split into five size ranges or groups prior to separation.