Dielectric material properties investigated through space charge measurements

This paper investigates means of exploitation of space charge measurement results in order to achieve information about chemical, physical and microstructural properties of dielectric materials. The derivation of quantities as mean volume density of space charge, threshold for DC space charge accumulation, apparent-trap controlled mobility is discussed and various applications to dielectric materials are shown. In particular, the differences of trapping behavior of polyethylene-based materials, as low-density polyethylene, cross-linked polyethylene and high-density polyethylene, the effect of additives containing polar groups, the evaluation of cellular polymeric electrets are discussed on the basis of the results of space charge measurements and the relevant extracted quantities.