Comparison of Digitizers for High-Precision Sampling Power Meters

This article compares different measuring equipment, especially sampling devices used in sampling power measuring standards. Several most frequently used digitizers are compared: HP3458A, NI 5922, and NI 4461. For calculating electric power, the following parameters are relevant: voltage amplitude, current amplitude, and phase difference between voltage and current. These parameters are obtained by the application of three different correction algorithms: 1) interpolated discrete Fourier transform; 2) 4PSF; and 3) phase-sensitive frequency estimation. The results are presented with several comparisons to get an insight into the performances of the digitizers that are suitable for precise power measurement, as well as, for calibration of equipment.