Improved Sampling Wattmeter for Low Frequencies (45 HZ-55 HZ)

We have strongly improved our sampling wattmeter for the measurement of low frequency power in the range of 45 Hz to 55 Hz. By using a more stable generator and by correcting for the dc offset in the signals, the basic accuracy in the phase measurement has been improved with a factor of 100 to the level of 20 mudegrees. This improvement has largely extended the applicability of the set-up. The more accurate phase measurement paves the way to e.g. characterisation of AC resistors, as well as power measurements at higher frequencies