https://doi.org/10.1351/goldbook.G02574
An
electric potential
difference between points in the bulk of two phases. It is measurable only when the two phases have identical composition (e.g. two copper wires). It is the difference of
inner electric potentials
in two phases. Symbol: Δαβϕ.
Source:
Green Book, 2nd ed., p. 59 [Terms] [Book]