Table 1 Overview of the investigated metallic and dielectric particle materials. Their type, name, chemical formula, and physical properties relevant to their electric field interaction and electron mobility are listed. The * marks the particle materials for which no detectable charge was observed. In these cases, the particles did not depart from the lower electrode. This indicates an insufficient charge accumulation to overcome adhesion and gravity. As a result, the charge quantification through the motion-based algorithm was not possible. However, this does not mean that their charge was not influenced by the electric field. Materials for which an agglomeration of moving particles was observed are marked by **. In the latter case, a charge sufficient for motion is observed, however, the developed method only applies to individually moving particles.

From: Measuring particle charges in high electric fields of gas insulation systems using tracking velocimetry