To determine the electrical conductivity of low-melting electrolytes (AIF(3)-rich, e.g. NaF/AIF(3) molar ratio = 1.2), a tube-type cell was used, applying ac-techniques with a sine wave signal with small amplitude in the high frequency range. One melt tested contained 55 mol% NaF and 45 mol% AIF(3) with and without addition of 2 wt.% alumina. Another melt tested contained 55 mol% KF and 45 mol% AIF(3) with and without addition of 2 wt.% alumina. The electrical conductivity data in the molten system can be described by a simple equation of the Arrhenius type: kappa = A e(-B/T) where K represents electrical conductivity (Omega(-1) cm(-1)), Tis temperature (K), A and B are constants for the measured system. The table presents the values of the coefficients A and B for the systems studied. (C) 2004 Elsevier Ltd. All rights reserved.