Virtual instruments: Uncertainty evaluation in the presence of unknown electromagnetic interferences

In a previous paper we analyze the electromagnetic immunity degree of a generic virtual instrument, in particular focussing on the measurement uncertainty evaluation. The analysis was performed by means of experimental tests subjecting the instruments to the normalized disturbances prescribed by the IEC-61326 standard. In this paper, starting from the results of the experiments, we define and validate a procedure which, by means of a simple and fast test, allows the assessment of the actual measurement uncertainty, taking into account the effect of the unknown electromagnetic disturbances that are actually present in the place where the measurement is performed.