the potential in volts of an inert metallic electrode measured in a system of an arbitrarily chosen ratio of [oxidant] to [reductant] and referred to the normal hydrogen electrode at absolute temperature; it is calculated from the following equation; where R is the gas constant expressed in electrical units, T the absolute temperature (Kelvin), n the number of electrons transferred, F the faraday, and E0 the normal symbol for the potential of the system at pH 0; for biologic systems, E0' is often used (in which pH = 7). Cf.: Nernst equation SYN: redox potential.