Fig. 11.6. Determination of the voltage between two points at or within the surface of a volume conductor.
(A) The potentials Φ_i and Φ_j at P_i and P_j due to the dipole may be established with scalar products with the lead vectors _i and _j , respectively.
(B) For determining the voltage V_{i j} between P_i and P_j, the lead vector _{i j} = _i - _j is first determined.
(C) The voltage V_{i j} is the scalar product of the lead vector _{i j} and the dipole .