Calculation of combined uncertainty according to the GUM approach : gamma spectrometry

Calculation of combined uncertainty of a measurement is an important quality measures, which gives the opportunity to compare measurement results. Without a combined uncertainty it is not possible to make such a comparison. Also, an uncertainty budget, i.e. an analysis of individual parameters' contribution to the combined uncertainty, is important since it reveals which parameters that dominate the combined uncertainty. Such knowledge can serve as a help in planning of measurements. This report presents briefly the process for the calculation of combined uncertainty according to the GUM approach. It also presents two tools the calculation, and an example of a gamma spectrometric measurement is given as well