Comparisons of contact-difference and contact methods for the measurement of membrane conductivity were made. It was found that the conductivity of the ion exchange membrane at infinite dilution can be accurately measured only by contact-difference method (CDM) in equilibrium with highly diluted electrolyte solutions. The dependence of the measured specific electrical conductivity and impedance of ion exchange membranes on the concentration, temperature, charges of counter ions and frequency of an electric field was discussed. Good agreement was found between the experimentally determined activation energy of ion-exchange membranes in the form of ions of different charges and the calculated activation energy using ab initio quantum chemical method. (C) 2017 Elsevier Ltd. All rights reserved.