What Does Applied Potential Mean?
The applied potential is the difference of potential measured between two identical metallic leads to two electrodes of an electrochemical cell. In an electrolytic cell, the applied potential drives the chemical reaction that would otherwise not happen in normal conditions. The reaction initiates the flow of ions and a resulting current.
Corrosionpedia Explains Applied Potential
The applied potential is comprised of two electrode potentials: the ohmic potential drop through each electrode and the ohmic potential drop through the solution.
A potentiostat is an instrument used to supply and control the applied potential, in addition to measuring the current flow between the counter electrode and the working electrode. It is an electronic circuit with operational amplifiers and a feedback system. It senses the current flowing between the electrodes and adjusts itself so that the potential difference between the two electrodes is maintained at the specified amount.
In the electrochemical cells the movement of the ions is from one electrode to the other, causing one of the electrodes to wear out and the other one to gain weight. The amounts of material loss and gain can then be used for analysis.
Applied potential is widely used in the electrochemical industry when carrying out various tests. It is one of the functions that accelerate the electrochemical corrosion testing processes.
The initiation and growth of corrosion fatigue cracks in stainless steel in natural sea water, is studied as a function of applied potential and other factors such as the stress range, cycles and frequency (i.e. on the wire rope).
An applied potential is used in electrogravimetry when separating and quantifying ions of a metal. The applied potential is usually adjustable and can be controlled to ensure that only the metal being analyzed is deposited on the electrode.
It is also used in processes that determine weight loss in metals.
An applied potential is used in several electrochemical corrosion tests, to study various corrosion forms such as general, galvanic and pitting occurring in metals, alloys, coatings and paints.