Résumé
Electrical properties of cyclohexane, a pure mineral oil, a mineral oil with additive and a silicon oil are studied in the frequency range of 10 −2-10 5 Hz. The paper reviews theoretical and practical basics for wide range dielectric spectroscopy measurements and puts into focus a method for estimating ionic mobility and diffusion coefficients in insulating liquids via data issued from low frequency spectra. Results obtained at different temperatures are presented and discussed.