The article presents the new electrical power measurement capabilities at LNE. The primary standard is based on sampling techniques. The power is calculated with a discrete Fourier transform algorithm, which is used to process the quantised samples of the voltage and current signals. Up to now, this primary standard was characterised only to measure active power for sinusoidal signals in the 45 Hz–65 Hz frequency range. From now on, the reactive power can also be measured and the frequency range has been extended to 400 Hz.

Key words

digital wattmetter
active and reactive powers
uncertainty budget