This document specifies a method for the determination of the relative loss of mass which a metallic powder undergoes when heated in a stream of pure dry hydrogen under specified conditions.

The purpose of this test is to evaluate a chemical powder characteristic which is of importance to the powder metallurgical industry. The test is not intended as a means for the determination of the content of specific elements (see Annex A and ISO 4491‑1).

The test method is applicable to unalloyed, partially alloyed and completely alloyed powders of the metals listed in Table 1 (see 7.2.1). It is not applicable to lubricated powders or to mixtures of metal powders.