A DAQ-based sampling wattmeter for IEEE Std. 1459-2010 powers measurements. Uncertainty evaluation in nonsinusoidal conditions

• The proposed wattmeter is based on commercial data acquisition boards.
• A correction stage is implemented to improve the accuracy of the instrument.
• The instrument uncertainty is evaluated in accordance with the GUM.
• An experimental correlation analysis is carried out for the uncertainty evaluation.
• The wattmeter can be used for of transfer standards under non sinusoidal condition.

This paper presents the evaluation of the metrological performances of a DAQ-based sampling wattmeter (DAQ-SW) for the measurement of IEEE Std. 1459-2010 power quantities in non-sinusoidal conditions. The instrument makes use of two commercial data acquisition (DAQ) boards, a non-inductive current shunt, a personal computer and a commercial software for data processing. Starting from the results of an experimental characterization of the two instrument channels with non-sinusoidal voltages and currents and a correlation analysis, the combined standard uncertainties of IEEE Std. 1459-2010 quantities are evaluated, following the approach of the ISO Guide to the Expression of Uncertainty in Measurement (GUM).