A 50 ppm low current multi-stage clamp-on current transformer

Summary form only given, as follows.An electronically-aided multi-stage technique is applied to a hand-held clamp-on current transformer which enables accurate low current measurements to be made over a wide dynamic range of operation, 0.5% to 100% of rated current, for use in conjunction with highly accurate power and energy meters, and harmonic power analyzers. The clamp-on current transformer can be used to measure currents in the range from 1 A to 200 A with ratio errors of less than 50 ppm in both magnitude and phase.