The Classical Potentiostat: Its Application To the Study of Passivity

The potentiostat, a device which maintains an electrode at a constant potential, offers a unique means of characterizing the active-passive behavior of metals. The classical potentiostat possesses the desirable combination of low cost, high accuracy, and circuit simplicity. The basic principles of this instrument have been developed and applied to the design of an instrument suitable for electrochemical studies of passivity. A quantitative discussion of the classical potentiostat shows that the total series resistance and the maximum current output completely characterize the performance of this instrument. Its performance can be increased by reducing its total series resistance and maximum current output. Both quantities can be experimentally determined. An improved classical potentiostat with an ultimate potential control of ± 1 millivolt is described in detail. 2.4.2