The barrier properties of coatings are vitally important in the protection of metals against corrosion. Water and ion ingression (e.g. Cl-), which penetrate to the metal/coating interface, generate electrochemically active sites and corrosion follows. Presently various experimental techniques, such as salt spray tests, are used to study corrosion protection properties of coatings and to predict their performance. However, most corrosion tests only provide a qualitative estimation of the protective properties of coatings without any information on the mechanism of protection or failure. Electrochemical Impedance Spectroscopy is widely used, not only to examine and rank the corrosion protection performance of coatings, but also to obtain important information on the kinetics of coating degradation and corrosion activity during exposure to a corrosive media. Localised scanning methods like the Scanning Vibrating Electrode Technique can be used to acquire localised electrochemical details that cannot be obtained by conventional techniques, which can shed yet more light on coating performance. Although the above techniques have all been used to investigate coatings, correlation between the results has not been conducted comprehensively. Uniscan M370微區(qū)掃描電化學工作站