Interpretation and use of data generated by particle characterization methods is highly dependent on the definitions of terms describing that data. It is extremely important that those terms be defined in precisely the same way both when comparing data from different characterization techniques and even when correlating data from the same technique.

It is likewise important that users of particle characterization methods and the data generated therefrom understand the principles of the methods, so that differences and similarities in the data can be interpreted in relation to those principles. That understanding can help to avoid disagreements when data from different characterization methods are compared.

The definitions contained in this terminology will aid in the interpretation of particle characterization data with respect to the method(s) used to produce that data.

1.1 This terminology covers the definitions of terms used in the description and procedures of analysis of particulate materials not ordinarily analyzed using test sieves. The terms relate directly to the equipment used in analysis, the physical forms of the materials to be analyzed, and selected descriptive data reduction and analysis formats.

1.2 Committee E29 on Particle and Spray Characterization believes that it is essential to include terms and definitions explicit to the committee’s scope, regardless of whether the terms appear in existing ASTM standards. Terms that are in common usage and appear in common-language dictionaries are generally not included, unless they have specific meanings in the context of particle characterization different from the common-language definitions.