David Lawrence, John S. Donnal, and Steven Leeb



Non-contact electromagnetic field sensors can monitor voltage and current in multiple-conductor cables from a distance. Knowledge of the cable and sensor geometry is generally required to determine the transformation that recovers voltages and currents from the sensed electromagnetic fields. This paper presents a new calibration technique that enables the use of non-contact sensors without the prior knowledge of conductor geometry. Calibration of the sensors is accomplished with a reference load or through observation of in situ loads.