Form factor (dispersity analysis)

In the case of irregularly shaped particles , for reasons of simplicity, an equivalent diameter is usually given to characterize the size. If the shape of the particle also has to be taken into account, a form factor can be defined from two equivalent diameters as the quotient of the two values, for example from the volume-equivalent and surface-equivalent sphere diameter

${\displaystyle k_{s,v}={\frac {x_{s}}{x_{v}}}}$

A special form factor is the Wadell sphericity , which is defined as follows: ${\displaystyle \Psi }$

${\displaystyle \Psi =k_{v,s}^{2}=\left({\frac {x_{v}}{x_{s}}}\right)^{2}={\frac {1}{k_{s,v}^{2}}}}$

Using the sphericity, Rittenhouse ( Lit .: 1) created a two-dimensional classification scheme with which particle images can be classified very easily.

literature

• GR Rittenhouse: Sedimentation near Junction of the Maquoketa and Mississippi Rivers, discussion. In: Journal of Sedimentary Petrology. Vol. 13, No. 1, April 1943, ISSN  0022-4472 , pp. 40-42, doi : 10.1306 / D426918E-2B26-11D7-8648000102C1865D .