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A More General Type A Evaluation



Ruediger Kessel, Raghu N. Kacker, Klaus-Dieter Sommer


The evaluation of uncertainty according to the Guide to the Expression of Uncertainty in measurement is the internationally agreed procedure to evaluate the complete result statement in measurement including measurement uncertainty. It distinguishes two types of evaluation: Type A and Type B. With the publication of the Supplement 1 to the GUM another method to calculate the result with uncertainty is available to the scientific community. In this paper we discuss the concepts behind the evaluation of Type A in the original GUM and in its supplement and the differences in the results. Metrology and test laboratories are often unable to collect a large number of sample values for the observed quantities in the uncertainty budget. In addition, often the knowledge about the statistical properties of the observation process is limited. Therefore better guidance is needed on how to find a proper standard uncertainty when the number of observations is small (
Proceedings Title
10th International Symposium on Measurement and Quality Control 2010
Conference Dates
September 5-9, 2010
Conference Location


uncertainty evaluation, type A uncertainty, non Gaussian observation process


Kessel, R. , Kacker, R. and , K. (2010), A More General Type A Evaluation, 10th International Symposium on Measurement and Quality Control 2010, Osaka, -1 (Accessed June 18, 2024)


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Created September 9, 2010, Updated February 19, 2017