Calibrator For Alternating Voltage, Current And Power

A computer-controlled calibrator capable of delivering AC sinusoidal and distorted voltage, current and power, with an accuracy of several parts per milion, is described. A combination of feedback and error-feedforward control strategy, together with the current comparator technique for very accurate ratio measurements, is implemented. The ppm stability of the calibrator permits the use of a multiplexing program for monitoring of several instruments over a long period of time.