Standard Electrode Potential. The Standard Electrode potential (E⁰) is the potential of a reversible electrode in equilibrium at standard state with an electrolyte concentration of 1 mol/liter or if a gas at 760 mm of Hg. The overall potential of a cell can be easily measured but the individual electrode/electrolyte potentials can be very difficult and is usually obtained by employing a reference cell and obtaining the potential of the other half cell by difference.

Further Information on this Topic can be found in the books of R.P.W. Scott by following the listed links