Noise resistance applied to corrosion measurements - VI. Partition of the current fluctuations between the electrodes

The most common cell configuration for corrosion monitoring based on electrochemical noise is constituted of two current-measuring working electrodes (WEs) connected by a zero-resistance ammeter (ZRA), so as to keep the two WEs at the corrosion potential. To correctly interpret the current fluctuations measured by the ZRA, the partition of the current between the two WEs produced by metal dissolution on a given WE was investigated through artificial-pit experiments carried out in various situations. The results were compared to the current partition predicted by a model developed in previous publications. Good agreement was obtained. This confirms that the current partition depends on the ratio of the electrochemical impedances of the two WEs. For identical electrodes at the same potential, the current is partitioned in equal amounts between the two electrodes. (C) 2002 The Electrochemical Society.