Charging of metal probes by a flux of particles

The charging current of a metal bar probe as a function of the mass flow rate of polyethylene, polypropylene and polystyrene particles that impact the probe while travelling through a pipe is presented in the paper. The probe is inserted into a PVC pipe through which the particles travel as carried by the flux of air. The dependence of the probe charging current on the mass flow rate is non-linear, mostly parabolic and quite different from that presented by a simplified mathematical model.