Abstract
A method was shown for measurement of the contact electrostatic field (Ek) between insulating powder and plain surfaces. The effect of air break down discharge was eliminated by forming a thin powder layer between two plain sample surfaces. Saturation and existence of finite value of the field was observed for toners and other polymer powders which were contacting on conductive or on insulating surfaces.
Dependence of the contact electrostatic field on the ionizing potential of metallic surfaces was noticed only for negative charging toners.
