“…In the controlled potential method, the working electrode is kept at a fixed potential such that only the desired reaction can take place. The current decreases as the process proceeds, so that the total amount of current (coulombs) must be determined by means of an external coulometer (1,9,10,11) or by experimentally fitting a mathematical expression for the current-time relationship (13). The controlled potential method, though possibly more versatile than the constant current procedure, requires more time and involves the additional step for calculating the total number of coulombs.…”