A method for measurement of triboelectric charging

A method for measurement of triboelectric charging is described. Triboelectric charges are produced by a cylinder, rolling on the surface of the test object. The rolling is performed at controlled speed and pressure. The voltage produced on the test object is continuously measured by an electrostatic voltmeter and the final value is taken as the result of the measurement. The only manual operation of the test, which is the removal of the cylinder from the test equipment, can easily be automated. The cylinder materials used in this evaluation are quartz and PTFE ("Teflon") respectively. Use of other materials should be possible but is not yet verified. The process of cleaning the cylinders is of the utmost importance. The developed process includes a heat treatment of the cylinders at 150/spl deg/C. The test method is shown to give a repeatability better than /spl plusmn/10% (1 /spl sigma/) in measurements of electrostatic conductive foils. This figure includes spread in the test object itself. Tests have been performed on different types of foil materials and the method discriminates well between them. Tests on hard materials are probably not suitable if the cylinder is made of hard, plane material. The method has to be further evaluated. Comparative measurements ("Round Robin tests") should be performed by other laboratories to evaluate the reproducibility of the method.