The dipole-dipole electrode array consists of two sets of electrodes, the current (source) and potential (receiver) electrodes. A dipole is a paired electrode set with the electrodes located relatively close to one another; if the electrode pair is widely spaced it is referred to as a bipole.[2] The convention for a dipole-dipole electrode array is to maintain an equal distance for both the current and the potential electrodes (spacing = a), with the distance between the current and potential electrodes as an integer multiple of a.[3] The electrodes do not need to be located along a common survey line.