ABSTRACT
Absolute repeatability in solution resistance lies in the range of a few tens of ohms, a value several orders of magnitude lower compared to the scatter in polarisation resistance. It is somehow striking to observe the scatter in repeatability among laboratories with some laboratories obtaining insignificant dispersion while others observed large scatter. One of the reasons was that some laboratories repeated the experiments more than three times and extracted the best three values for statistical evaluation. Most modern computer controlled potentiostats provide integrated software routines to calculate this. In order to evaluate the reliability of such routines, corrosion current densities were extracted from selected polarisation curves by the coordinators. Polarisation curves are usually used to identify the reactions determining the electrochemical response and the corrosion behaviour. All laboratories found a very similar shape for the polarisation curves. In the present systems, some doubts exist about the electrochemical behaviour of the alloy components.
