Comparison of Symmetrical and Asymmetrical Cells by Statistical and Wavelet Analysis of Electrochemical Noise Data

Abstract

The most common cell configuration for electrochemical current noise (ECN) measurements consists of two identical working electrodes (WE) known as symmetrical cell, connected by a zero-resistance ammeter (ZRA). The analysis of ECN data is complicated by its reflection of the behavior of two identical WE, but it would be facilitated greatly if the behavior of one of two WE were measured separately. According to an earlier theoretical model, an asymmetrical cell with a large difference in size between two WE, which are otherwise identical, allows the measurement of ECN on the small electrode while allowing free corrosion to proceed. In this paper, the ECN signals obtained on the symmetrical cells are compared with those carried out on the asymmetrical cells by statistical and wavelet analysis methods. Three advantages of the asymmetrical cells for measurement of ECN data are clearly seen: the time scale preserving of current transients, the increase of amplitude of current transients, and the detection of a higher number of events.