ASTM International Standard Test Method for Fisher Number of Metal Powders and Related Compounds ASTM B330-05

1.1 This test method uses air permeability to determine an envelope-specific surface area and its associated average equivalent spherical diameter (from 1 to 50 m) of metal powders and related compounds. The powders may be analyzed in their "as-supplied" (shipped, received, or processed) condition or after they have been de-agglomerated or milled by a laboratory procedure ("lab milled") such as that specified in Practice B 859. The values obtained are not intended to be absolute but are generally useful on a relative basis for control purposes. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.