Average Particle Size

All particle systems contain a range of particle sizes, unless specially manufactured. The distribution can be expressed on number, surface, mass or volume basis. To locate the center of a distribution several methods are used, the most important being mode, median and (arithmetic) mean.

Mode: The most frequent particle size in the distribution. A distribution can have more than one mode (Bimodal, Trimodal, etc.).

Median: The particle size that divides the distribution into two halves, where 50% is finer than the median and 50% coarser.

Mean: The most common statistical average. The sum of all particle sizes that occur divided by the total number.