0.1Hz Coulometry is an ideal method of monitoring pitting, crevice and other localised corrosion on passive metals such as stainless steel. It has a useful current range of 20nA to 50mA without the need for range changing. This allows it to monitor rapid sporadic events with ease.
Readings are taken at a rate of 50Hz. The accumulated absolute charge over a 10 second period is presented on a histogram in decade bins. A corresponding line graph plots the cumulative charge of each bin over time. In this way, steady crevice corrosion is represented by a constant gradient and large events create conspicuous steps.