Pore size rating

The diameter of a particle which normally will be retained by the filter. This applies whether the pore size rating is nominal or absolute.

FAQ
A pore size rating is the diameter of a particle which will normally be retained by the filter. This applies whether the pore size rating is nominal or absolute.
Pore size of sterile filtration: 0.2 Microns vs. 0.22 Microns.
A micron can be defined as a unit of measure in the metrical system level to 1 millionth of a meter in its length. The usual cross-section of the hair of a human is around 50 microns. A micron rating can show the capability of a filter (liquid) to extract particles by their size.