Zeta potential is a measure of the charge on a particle surface in a specific liquid medium. This value of surface charge is useful for understanding and predicting interactions between particles in suspension. Manipulating zeta potential is a method of enhancing suspension stability for formulation work, or speeding particle flocculation in applications such as water treatment. Zeta potential is measured on the SZ-100 using the technique of electrophoretic light scattering where particle motion is detected in an applied electric field.