equivalent diameter

Diameter of a spherical particle which will impart geometric, optical, electrical or aerodynamic behaviour identical to that of the particle being examined.

Note: Depending on the measurement method applied, various equivalent diameters could be defined for the same particle. These different diameters are only indirectly comparable since different particle properties are being measured, e.g. geometric diameter, diameter according to dielectric mobility, diameter according to light scattering properties. Nevertheless, the generic term “particle diameter” is often used for all of them.