An apparatus for measuring the Wien effect in suspensions

The deviation from Ohmʹs law characterized by the electrical conductivity (EC) increasing with electrical field intensity is named the Wien effect. In a forthcoming article we will report on a study aimed at utilizing Wien effect measurements in suspensions for characterizing the interactions between electrically charged clay particles and counter-ions. This article reports on the construction and testing of a low-cost apparatus, SHP-1, which generates short high-voltage pulses that make it possible to measure the Wien effect in solutions and suspensions at electrical fields up to 2×107 V m−1. The apparatus, electrode cells and measuring procedure were tested by measuring the Wien effect in dilute solutions of strong electrolytes of two valences and various concentrations, and the results were in acceptable agreement with previous experimental results and theoretical predictions. Electrode polarization and Joule heating phenomena were evaluated by measurements at varying electrode spacings, and their extent was found to be relatively limited for electrode spacings of about 1–5 mm.