Patent ID: 7660682

Claim:
A meter device for measuring electrical energy comprising: circuitry for measuring at least one parameter of electrical energy monitored by the meter device; a storage device for storing at least one calibration factor for compensating for errors associated with at least one of at least one external current transformer (CT) and at least one external potential transformer (PT) that operates on the electrical energy provided to the meter device; at least one processor for processing the at least one calibration factor for adjusting the measured at least one parameter of electrical energy for compensating for the errors when measuring the at least one parameter of electrical energy; and at least one communication port for receiving the at least one calibration factor from an external device, wherein calibration factors of the at least one calibration factor correct for errors measured during testing of respective test points of a series of test points, each test point corresponding to a different current magnitude for modeling non-linearity of errors associated with a range of current magnitudes for current signals of the electrical energy operated on by the at least one external CT, and at least one calibration factor corresponds to each test point, and wherein at least one calibration factor for the at least one external potential transformer (PT) is determined from one voltage test point.