Odd random phase multisine EIS for organic coating analysis

In this paper the different steps involved in an integrated methodology to measure, analyze and model electrochemical systems in a correct and reliable way are shown for Al-rich metallic coated steel with an additional organic coating. This methodology is based on the use of an odd random phase multisine excitation signal and was proposed by our group previously. The use of this multisine excitation signal decreases the measurement time. Moreover, it allows to perform a rigourous data-analysis and to quantify the signal-to-noise ratio, the level of non-linear and non-stationary behaviour. It was shown that by using this technique the optimal measurement conditions can be chosen based on a trade-off between signal-to-noise ratio and non-linear behaviour. Moreover, in the modeling procedure the noise, non-linearities or non-stationarities can be taken into account. The methodology allows a statistical evaluation of the proposed model for the coated metal, indicating whether model errors are still present or not.