Calibration of the thd functions of electrical standards

The paper describes a test procedure, the test waveforms, and the reference equipment used to calibrate the voltage and current total harmonic distortion (THD) measuring functions of multi-function electrical standards. It also shows that it is possible to establish traceability to the SI units for the THD measurements by measuring the voltage and power of the test waveforms with voltmeters and wattmeters that are traceable to SI. Results of recent calibrations are discussed.