4.2.1 Metrologically relevant parts in general

To be able to define whether a function/functionality of a physical module is to be considered as metrologically essential, it is necessary to know its influence on the metrologically relevant output data.

Therefore, when observing the configuration of a measurement system an analysis should first be carried out indicating which functions within this system or part of such system could be considered as being essential for its metrological behavior and/or of relevance to its application for legal purposes.

The parts attributing to or comprising these functions shall be taken into account in the subsequent evaluation.

The next stage will be the analysis of whether and by what means such functions could be approached and/or influenced by external sources other than the measurand.