In potentiostatic coulometry, potential of the working electrode is held constant
(static). This technique is similar to electrogravimetric method wherein electrolysis is
carried out at a fixed potential. However, the former is more convenient than
electrogravimetric method by the fact that the weighing step at the final stage (mass
of the product) is avoided. Hence, controlled potential technique can therefore be
applied to systems that yield deposits with poor physical properties (antimony) and to
reactions that do not give solid products at all.