ASTM B821-23

4.1?The method of powder dispersion in a liquid has a significant effect on the results of a particle size distribution analysis. The analysis will show a too-coarse, unstable, or nonrepeatable distribution if the powder has not been dispersed adequately. It is therefore important that parties wishing to compare their analyses use the same dispersion technique.

4.2?This guide provides ways of deriving dispersion techniques for a range of metal powders and compounds. It should be used by all parties performing liquid-dispersed particle size analysis of all of the materials covered by this guide (see 1.1, 1.2, and 4.1).

4.3?Table 1 provides some dispersion procedures that have been found useful and consistent for the particular materials listed there. These are only 4.4?This guide should be used in the preparation of powders for use in Test Methods B761 and B822 and other procedures that analyze metal powder particle size distributions in liquid-dispersed systems.

1.1?This guide covers the dispersion in liquids of metal powders and related compounds for subsequent use in particle size analysis instruments. This guide describes a general procedure for achieving and determining dispersion; it also lists procedures that have been found useful for certain materials.

1.2?This guide does not include specific procedures for dry dispersion of particulate materials. It only indicates when liquid dispersion is not appropriate and dry dispersion must be utilized (see 7.1.2.1). For guidance on development of methods of 1.3?This guide is limited to metal powders and related metal compounds. However, the general procedure described herein may be used, with caution as to its significance, for other particulate materials, such as ceramics, pigments, minerals, etc.

1.4?UnitsThe values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.