Σύνδεσμος Οδηγία για την αβεβαιότητα στους αναλυτικούς προσδιορισμούς – GUM
Guide to the Expression of Uncertainty in Measurement.
The 'GUM Workbench' program is used to analyze the uncertainty of physical measurements and calibrations. The analysis and computations follow the rules of the 'ISO guide to the expression of uncertainty in measurement' and the requirement document EAL-R2 of the 'European cooperation for Accreditation of Laboratories'.
Computation examples of the EAL-R2 can be analyzed with the help of the program. They are included with the software package as example models.
GUM Workbench supports a systematical procedure in building an uncertainty analysis as required by the EAL document. Starting with the mathematical equation which models the physical relationship of quantities in the respective measurement, the data needed for the analysis, like the standard uncertainty or the distribution of values, is interactively requested. Appropriate classification of the input values according to the available information controls the analysis process.
The result of the analysis is a clear table of the uncertainty budget. This table holds all used measurands with their symbols and values, the assigned standard uncertainty and actual degrees of freedom, the sensitivity coefficient worked out by the model equation and their contribution to the standard uncertainty of the result of the measurement. In the end the complete result of the examination is presented as a value with connected expanded uncertainty and automatically selected coverage factor. All values are rounded to a convenient number of decimal places.
For documentation purposes the result of the uncertainty analysis together with all input data can be printed as a report. All input texts are part of the printout and used for a clear and structured documentation. Before the actual printing process is initiated you can check the result in a preview window.
The analysis together with all the input (the model equation, the values and all the texts) can be saved in a file with a selectable name. That way the examination is available at any time for a later check.
Each saved analysis can be used as a starting point for new uncertainty analyses utilizing the same model but using new or changed data. Therefore the program is suited especially for the examination of the influence of the various values and their accompanying uncertainties on the result. |