Multivariate analysis of impedance data obtained for coating systems of varying thickness applied on steel

The presented approach does not use the stage of an equivalent circuit selection. Using multivariate methods (e.g., principal component analysis - PCA) it is possible to extract specific information direct from the measured data without the need of an a priori adoption of a specific equivalent circuit. Results of multivariate analysis of a coating system with varying number of layers on steel as a function of immersion time in 3% NaCl using this novel approach are presented. The benefits of this approach are discussed.