Traceability of electrical quantities obtained by sampling

The substitution of the traditional analogic measurement and processing techniques with sampling methods is a trend in modern metrology. Many commercial instruments perform this determination by means of their internal firmware. An analysis is necessary when sampling instruments are employed within a laboratory, for the determination of one or more quantities. However, this analysis is possible only under some specific circumstances, where both the characteristics of the samples and the processing algorithms have to be known.The paper will consider the samples as input for the determination of given quantities and the methods to evaluate the uncertainty of the results from the uncertainty of the samples and their correlation. The example is derived by the uncertainty evaluation of the INRIM system for the precision measurement of the power, where the determination of the accuracy has been accomplished both by an almost analytical approach followed by a numerical evaluation.