A basic voltmeter can be used to measure the potential, which can then be compared to a standard reference electrode such as a Saturated Calomel Electrode (SCE) or Silver Silver Chloride (Ag/AgCl) and a cell containing 3M KCl. Another method is to evaluate redox potentials (peak-to-peak separation potential) by performing a experiments using a standard redox probe potassium ferric cyanide [K3Fe(CN)6] Estimating the Ag/AgCl electrode potential by conducting the hydrogen evolution reaction (HER) with a Standard Hydrogen Electrode (SHE) in 1M HCl, (purging the hydrogen gas continuously, at 1 atm pressure)

The electrochemical cell based on two or three electrode system of working electrode (WE), reference electrode (RE) and counter electrode is placed in a suitable electrolyte solution. During the redox process, the solution resistance will rise if the gap between the WE and RE is wider. As a result, as indicated in Fig 1, it is essential to place the WE and RE as close as possible. If the experiments are conducted in non-aqueous or ionic liquids, the constant distance needs to be maintained throughout the experiment, and monitoring is recommended. The Luggin capillary setup can be utilized to lower the WE...

The KCl solution not only serves as a reservoir for Cl-, but it also aids in the transfer of electrons and ions between the calomel electrode and the solution, which is required for the electrode to work effectively. The electrode potential can be controlled by changing the concentration of the KCl solution, which also acts as a salt bridge. The potential of the Saturated Calomel Electrode (SCE) is governed by the Cl- ions which are in equilibrium with Hg and Hg2Cl2.

When the electrodes are in a single container, an electrochemical cell can function without a salt bridge, because electron flow happens naturally within the system. However, if the electrode is situated in two different containers, as shown in Fig 1 and Fig 2, the salt bridge aids in transferring charges from one electrolyte to another. Inert electrolytes such as KCl or NaOH must be used to fill the salt bridge. These electrolytes have similar migration rates and conductivities, and they do not participate in any chemical reactions in electrolytic cells.