A validation of a THD measurement equipment with a 24-bit digitizer

A high performance THD measurement equipment based on the National Instruments NI PXI-5922 24-bit Flexible-Resolution Digitizer was developed at CMI. This paper describes the validation method and achieved results. The validation was done in two steps; in the first step a low distorted signal using ultra-pure generator was utilized. In the second step was done a validation of a high level THD measurement using a calculable THD standard.