An analog electronic interface to measure electrical conductivity in liquids

Measuring conductivity in aqueous solutions is a problem which is not easy to solve due to the differences in mass and mobility that exist between ions conduction and electrons. Additionally, it is necessary to keep in mind the interaction processes electrode-solution. As a consequence, the electrolytic conductivity cell has to be polarized with alternating voltage of adequate amplitude and frequency in order to extract the correct information. In this paper an electronic conditioning circuit is presented which converts electric conductivity into a value of continuous voltage. A hardware solution is proposed to do the conductivity temperature compensation. Experimental results obtained in KCl solutions are also offered by following a close discussion of them.