Electrode systems for dielectric strength controlling the electro-dielectrophoretic effects

Two kinds of electrodes showing different behaviour with respect to the impurity particles present in a dielectric fluid have been designed and built. Both electrodes have a uniform field region. The first kind is designed in order to avoid as far as possible the attraction of impurity particles into the test volume, whereas the second one is designed to the opposite aim. This is achieved by means of a peculiar choice of the electrode profiles, which control the motion of particles by means of different field patterns. Some sets of experimental results on transformer oil confirming the theoretical expectations are presented and discussed.