CALOMEL ELECTRODE2

"The equilibrium electrode potential is a function of the chloride concentration of the internal electrolyte (""filling solution""). The electrolyte is practically always saturated potassium chloride (hence the name: ""saturated calomel electrode,"" SCE, ""calomel"" is an old name for mercurous chloride), producing a potential of 0.244 volt against the standard hydrogen electrode at 25 oC. "