The method specified can also be applied to the examination of other powders or granules which are insoluble in water. It is neither applicable to hydrophobic nor pelletized materials. In the test apparatus the material under test, dispersed in water, is brought into centrifugal motion by a system of rotating jets of water. he water flushes the fine particles through the sieve, the coarse particles being retained on the sieve. The residue on the sieve is dried and weighed. - Cancels and replaces ISO 787/18-1973 and constitutes its technical revision.