What is the purpose of storing a calomel electrode in a KCl solution?

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.