scope:

This document describes the principles and proper use of gravitational photosedimentation techniques for the characterisation of dispersed phases of suspensions and emulsions. These techniques monitor the gravity-induced phase separation of particulate materials dispersed in liquids by recording photometric signals (i.e., intensity of transmitted or scattered light) as a function of vertical position and/or measurement time.

This document covers neither particle migration by centrifugal, electric or magnetic forces nor sedimentation at high particle concentrations (e.g. zone sedimentation). Moreover, it does not deal with the determination of properties other than sedimentation velocity and particle size (i.e. neither particle concentration, particle shape, particle density, zeta-potential nor apparent viscosity).

Additionally, this document does not cover alternative techniques for gravitational sedimentation including balance based and X-ray based techniques.

NOTE This document does not purport to address all the safety problems associated with its use.