A NUMERICAL KRAMERS-KRONIG TRANSFORM FOR THE CALCULATION OF DIELECTRIC-RELAXATION LOSSES FREE FROM OHMIC CONDUCTION LOSSES

A numerical Kramers-Kronig transform is described which allows the cal culation of dielectric relaxation losses from dielectric constant data measured at a limited set of frequencies differing by a factor of 2. Conversion formulas for both the central frequencies and for frequenci es near the edges of the experimental frequency window are derived. Th e approach used can be extended easily to measurement frequencies with a different logarithmic spacing. Using this conversion, relaxation an d dissipative, conduction losses can be separated. In this way Ohmic c onduction precesses and simultaneously occurring relaxation processes like dipole or space-charge relaxations can be analysed independently. The results of some simulations and of calculations on experimental d ata for poly(vinyl-chloride) are used to illustrate the potentials of the epsilon' to epsilon '' conversion.