Design Aspects of Electrochemical Noise Measurements for Uncoated Metals: Electrode Size and Sampling Rate Available to Purchase

Observed and simulated electrochemical noise (EN) from general and localized corrosion on uncoated metals was used to test theoretical concepts regarding the relation of electrode area and corrosion rate to noise. Electrode area influences noise resistance, which emphasized the importance of the choice of electrode area in design of noise measurements. The possibility of obtaining mechanistic information by spectral analysis does not appear promising. Direct inspection of time-domain data may be more useful than statistical or spectral analysis to obtain mechanistic information. Direct inspection could be facilitated using a large area ratio between the electrodes of the electrochemical current noise probe. Simulated and measured noise indicated a sampling rate of 1 Hz may be too low in some instances.