Study of the dielectric properties of flame retardant insulation during thermal ageing

Abstract

Abstract. The complex permittivity of the flame retarding cables with combined insulation has been investigated during a long-term thermal ageing. The both parts of epsilon* were measured in the very low frequency range by using a special instrument made for this purpose. They were also measured with help of the time domain dielectric spectroscopy. The frequency dependences of epsilon* were compared with those calculated by the Cole - Cole dispersion formula. The dc electrical conductivity sigma0 was derived by means of numerical fitting.