What is the difference between a potentiostat and a galvanostat?

A potentiostat controls the potential and measures the resulting current. A galvanostat controls the current and measures the resulting potential. Most modern instruments are combinations of potentiostats and galvanostats.

  • Potentiostatic techniques are often used in analytical applications or when reactions are triggered selectively.
  • Galvanostatic techniques are often used in situations where a Reference Electrode (RE) is not available. When combined with a known electrode surface area, it offers a reliable and reproducible alternative for quantitative and comparative electrochemical studies. Its ability to maintain a constant current density, even with changes in the system’s resistance, allows for highly reproducible experiments, ensuring precise control over current conditions and minimizing the impact of resistance variations. This feature makes it particularly valuable for quantitative analyses, such as determining reaction rate constants and charge transfer coefficients.