Abstract: Disclosed is a method of determining the eccentricity of the insulation on a round wire without making electrical contact with the wire. The insulated wire is passed between two pairs of opposing electrodes, pair A-C and pair B-D, positioned at a known distance from the insulated wire and spaced apart azimuthally at a known angle. Known, out of phase, alternating voltages are applied to each pair of electrodes. Signals are generated from the four electrodes that are proportional to (1) v.sub.A -v.sub.B +v.sub.C -v.sub.D and (2) -v.sub.A -v.sub.B +v.sub.C +v.sub.D, where v.sub.A, v.sub.B, v.sub.C, and v.sub.D are the voltages on electrodes A, B, C, and D, respectively. From those signals the eccentricity of the insulation on the wire can be determined by ##EQU1## where .vertline.q.vertline. is the magnitude of ##EQU2## The direction of the eccentricity can be determined from the difference in phase between the two signals.