Plot of the potentials recorded from the quadrupole of Figure 9 in an infinite volume conductor and an insulating cylindrical volume conductor of radius 1 extending from z = -5 to z = 5. Recordings made with a monopolar electrode (reference recording) and a bipolar recording are shown. The logarithm of the absolute value of the potential is plotted rather than the potential in order to better show the behavior of the potential far from the source. Note that plots extend only from z = 1 to z = 5 although the cylinder extends from -5 to 5. This demonstrates that bipolar recordings far from the source yield a constant value independent of electrode location.