Impedance measuring equipment

Franz cells (Ø=0.90 cm, V=6 ml, PermeGear, Hellertown, PA, USA) equipped with four electrodes and connected to a potentiostat from Ivium Technologies (Eindhoven, The Netherlands) are used to study impedance characteristics of membranes, including skin, leafs, etc. Two platinum wires serve as working and counter electrodes and two Ag/AgCl/3M KCl electrodes from World Precision Instruments (Sarasota, FL, USA) are used as sensing and reference electrodes. The equipment allows impedance measurements at frequencies up to 6 MHz.