Definition - What does Galvanostatic mean?

Galvanostatic refers to an experimental technique whereby an electrode is maintained at a constant current in an electrolyte. This technique is used to measure corrosion rate and electrochemical reactions.

Galvanostatic, like potentiostatic and potentiodynamic, is a polarization technique that allows for the controlled polarization of metal surfaces in electrolytes, in order to directly observe cathodic and anodic behaviors.

In galvanostatic tests, the change is plotted in potential verses time at constant current. A constant DC current is applied to the metal of interest while it is immersed in the electrolyte.

Corrosionpedia explains Galvanostatic

The galvanostatic mode is an electrochemical measuring mode for electrochemical analysis or for the determination of the kinetics and mechanism of electrode reactions based on the control of the current flowing through the system. The control apparatus used is called a galvanostat.

The galvanostatic method consists of placing a constant current pulse upon an electrode and measuring the variation of the resulting current through the solution. It is used for measuring the rate of an electrochemical reaction. This technique is used for Tafel curves and linear polarization measurements, and its applications include corrosion rate measurement.

Galvanostatic polarization is an alternative to potentiostatic polarization. In galvanostatic polarization measurements, the current between working and counter electrodes is controlled, and the potential between working and reference electrodes is automatically adjusted to the value required to maintain the current. The potentiostatic polarization curve provides considerably more information about passivity than does the galvanostatic curve.

In the galvanostatic approach to measure linear polarization resistance:

  1. A small current is applied.
  2. The electrode potential changes.
  3. The potential change is measured.
  4. Overvoltage vs. current is plotted and the slope calculated.
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