On the use of windows for measurements of R.M.S., active power and harmonic parameters.

Weighing windows have been suggested so as to cut the error that non-coherent sampling induce in the measurement of r.m.s., power and harmonic parameters. The link between the weighing and the Swerelein algorithms is shown. The paper also presents an algorithm for finding the amplitude and phase of harmonics based on the frequency characteristic of the used window. The suggested windows allow the reduction of the error due to non-coherent sampling to 0.1..0.3ldr10^-6 with the measurement time of 2.5 to 3.5 periods of fundamental harmonic.