This knowledgebase contains all you need to understand potentiostats, electrodes and how to use them to perform for example coating research or analyze paint. It will give an intro...
In this section the reasons for choosing a certain DC potential is explained. The advantages of using Ecorr as a reference point will be presented as well as how to choose in PSTrace to use potentials versus the reference electrode or versus Ecorr.
In this section of the handbook the Warburg Impedance and the Constant Phase Element (CPE) are introduced, which represent electrochemical effects with no corresponding real electronic components. Furthermore, some equivalent circuits for typical corrosion systems are presented.
In this chapter the two main ways of visualizing Electrochemical Impedance Spectra (EIS), the Nyquist and Bode plot, are presented and it is explained how different EIS of easy electronic circuits will be plotted in the Bode and Nyquist plot. This demonstrates the advantages and disadvantages of the two plots as well as serving as a foundation to understand the analysis of EIS by utilizing equivalent circuits.
To understand the foundation of corrosion current measurements the Tafel plot and the Evan’s diagram are explained. The connection between a polarization curve and the Evan’s diagram is explained and how to extract the corrosion current from a polarization curve.
In this chapter the Open Circuit Potential (OCP) and the Corrosion Potential are introduced. The principles of reference electrodes as well as the 0 V by convention potential of the standard hydrogen electrode (SHE) are explained.
In this extensive section Polarization Curves are discussed. How to setup your equipment, the choice of parameters as well as the data processing is discussed. This will enable you to record a polarization curve and extract the corrosion rate from it by using PSTrace 5. Furthermore, the polarization curves and Evan’s diagrams for passivation films (thick and thin) are discussed. This section closes with a brief description of crevice and pitting corrosion.