The electrical properties of particles especially the volume resistance of bulk particles have decisive implication on a multitude of processes in the process engineering such as, product qualification or fire and explosion protection. Since the charge transport in a disperse system and a homogeneously solid is different, the product properties of the particles and the fluid are crucial for the volume resistance. In this work the dependence of the volume resistance on the internal structure of the bed, the relative humidity, the conditioning time at different climates and the average particle size was investigated. All measurements were carried out in a concentric measuring cell.