Aging assessment of insulating materials through broadband dielectric measurements: the appropriate frequency choice

In this article the dielectric response of differently filled insulating materials is studied. The contribution of polymer additives showed to influence both the dielectric spectrum and conductivity values of the considered materials. Among the different analyzed frequencies, it has been concluded that the highest frequency region (e.g. 100 kHz), related to the dipolar polarization, is affected significantly by additives and it depicts a monotonous increase with aging time, hence it could be suitable as an aging marker for cable nondestructive diagnostics.