GUM
Definition
Guide to the Expression of Uncertainty in Measurement. The international standard, maintained by eight metrology and standardisation bodies, that defines Type A and Type B uncertainty evaluation, uncertainty propagation, and expanded uncertainty. ISO/IEC 17025 requires laboratories to implement GUM-consistent uncertainty procedures.
Related terms
- Combined standard uncertainty
- The overall standard uncertainty of a result, obtained by combining all Type A and Type B component uncertainties in quadrature (square root...
- Expanded uncertainty
- The combined standard uncertainty multiplied by a coverage factor k, chosen to achieve a stated coverage probability. For a normal distribution, k...
- Type A uncertainty
- Uncertainty evaluated by statistical analysis of a series of observations. The standard uncertainty is the standard deviation of the mean (standard error)...
- Type B uncertainty
- Uncertainty evaluated by means other than statistical analysis of repeated measurements. Sources include calibration certificates, instrument specifications, reference data, and expert scientific...
- z-score (proficiency testing)
- A performance statistic in PT defined as z = (x - X) / s_PT, where x is the laboratory's result, X is...
Explained in
- Measurement Uncertainty and Proficiency TestingGuide to the Expression of Uncertainty in Measurement. The international standard, maintained by eight metrology and standardisation bodies, that defines Type...