Abstract Anodic and cathodic polarization curves have been determined in the current density range of 0.005 to 1 A/cm 2 and in the temperature range of 40 to 80°C in 30% KOH, using a measuring method that allows direct ohmic drop correction at zero distance from the electrode surface. Tafel linearity has been confirmed on all the materials tested, as well as the presence of films whose considerable ohmic resistance depends on temperature but remains unchanged throughout the cd range investigated. The possible nature of such films, whose resistance is to be included among the basic parameters of electrode performance, is discussed.