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Review on methods to estimate measurement uncertainties – the various concepts of the "GUM" and its supplements

Kolloquium der Abteilung 5

In metrology, an important task is the determination of indirect measurands derived from observations of direct measurands and by an estimation procedure based on a model. The model includes the mathematical description of the physics and as well the statistical description of a non-deterministic behavior. A measured quantity value is an estimated value and the information on its uncertainty. An overview will be presented on different ways to determine the uncertainty of an indirect measurand if information on the uncertainty of the direct measurands is given. The appropriateness of different methods depends on the models that define the relation between the measurands. The Joint Committee for Guides in Metrology (JCGM) provides for guidelines on this topic, which will be summarized. The different methods will be illustrated by applying them to one example physics problem.