A practical approach to evaluate the measurement uncertainty of virtual instruments

Virtual instruments need a metrological characterization that is coherent with their philosophy. This paper analyzes the main features that a method should have to be suitable for the evaluation of the measurement uncertainty of virtual instruments. Especially the advantages of numerical methods are considered. For example, the general classification of error sources allows to include a lot of devices. Moreover, numerical methods are able to perform analysis directly on measured values, but it can introduce alteration on estimated parameters. Two implementations of these principles are presented. The former is a virtual analogy of a test bench. The latter exploits IVI (interchangeable virtual instruments) simulation capability. The analysis doesn´t require code modifications and is independent of hardware and software structure.