Abstract: An electrode system for monitoring potentials between electrodes that includes a structure having a surface, a first electrode, a second electrode, an electrolyte, and a monitor to measure the potentials between the first and second electrodes. The first electrode is connected to the surface of the structure. The second electrode and surface of the structure are each in direct physical contact with the electrolyte so that a potential exists between the first and second electrodes. In certain embodiments, the electrode system may further include a reference electrode that is in physical contact with the electrolyte and physically isolated from the first and second electrodes so that a potential exists between the reference, first, and second electrodes. Optionally, the electrode system further includes an apparatus for measuring a background change in the potentials between electrodes and compensating for this background change.