Patent ID: 8878517

Claim:
An intelligent electronic device comprising: a sensing circuit having one or more sensors for sensing at least one parameter of an AC electrical service, each of the one or more sensors generating a first signal representative of the sensed parameter; a plurality of gain-adjustable channels, each channel having at least one gain adjustment circuit for individually adjusting a gain factor and each channel comprising at least one first signal generated by the one or more sensors, the at least one first signal representative of the sensed parameter; one or more computer-readable storage devices; a plurality of calibration factors stored in the one or more computer-readable storage devices, the plurality of calibration factors corresponding to a plurality of calibration measurements, the plurality of calibration measurements comprising measurements of a second signal representative of a known value of the parameter at a plurality of signal amplitudes in each of a plurality of calibration ranges; and a processor that determines a calibrated value for a measured data point using interpolation of the results of the plurality of calibration measurements.