Distance and position reference electrodes are important in various fields such as electrical engineering, geophysics, and neuroscience because they provide a stable and reliable reference point for measurements.

In electrical engineering, distance and position reference electrodes are used in grounding systems to ensure safety and reliability

Dear Ehsan Allahyari , in a three-electrode potentio controlled measurement, the current flowing between the working and the counter electrodes is adjusted to maintain a set voltage between the working and the reference electrodes. If the electrolyte you are using is not conductive enough or if the distance between the reference and the working electrode, the true applied voltage is not the desired one, but it is decreased by a term called ohmic drop, equal to the resistance between the working and the reference electrode multiplied by the current. The potential "seen" by the working electrode is actually smaller than the applied potential. Hence the current response will be underestimated...

Please our resources on our website for further explanations:

https://www.biologic.net/topics/ohmic-drop-correction-a-means-of-improving-measurement-accuracy-with-potentiostats/

https://www.biologic.net/wp-content/uploads/2019/08/battery-corrosion-ohmic-drop_electrochemistry-an27.pdf

https://www.biologic.net/wp-content/uploads/2019/08/battery-ohmic-drop_electrochemistry-an28.pdf

https://www.biologic.net/wp-content/uploads/2019/08/battery-ohmic-drop_electrochemistry-an29.pdf

I hope this helps,

Best regards,

Nicolas

Ehsan Allahyari in an electrolytic cell there is a resistance due to dissolution, therefore, a conductive medium is provided by adding a supporting electrolyte. The resistance of the solution (Rsol) is equal to the sum of the resistance between the counter electrode and the reference electrode (Rc) and an uncompensated resistance, which is called Ru. That is: Rsol = Rc + Ru. Ru is an uncompensated resistance that appears between the working electrode and the reference electrode. Then, the importance of the distance between the electrodes lies in the fact that the greater the distance between the reference electrode and the working electrode, the greater will be Ru, which, not being compensated, the real potential experienced by the working electrode is not the one that is imposed, it is lower, in terms of absolute value. This is known as ohmic drop, because it is a drop in potential due to a resistive effect. Although many potentiostats have the option to compensate the ohmic drop, the ideal is to avoid this effect as much as possible, because there will never be a complete compensation, and also because the compensation of the ohmic drop generates effects on the peak current.

In practice, the effects of ohmic decay are annoying, for example, they affect the reversibility of the system studied by cyclic voltammetry, causing a system that is reversible, apparently appear quasi-reversible, which prevents the application of certain equations.

I hope my explanation helps you. Regards.