engleski

Estimation of test methods maesurement uncertainity in concrete and clay laboratory

One of the requirements of HRN EN ISO/IEC 17025 standard is measurement uncertainty for testing and calibration meth-ods evaluation. Paper describes approach of laboratory to measurement uncertainty estimation, and gives specific ex-amples how measurement uncertainty is estimated for par-ticular groups of methods. Test methods can be categorized as qualitative and quantitative methods. For qualitative meth-ods numeric expression for measurement uncertainty is im-possible, but particular uncertainty components can be given. For quantitative test methods it is possible type A and type B of measurement uncertainty estimation. Importance of both measurement uncertainty types estimation, where it is possi-ble, is emphasized. Type A of measurement uncertainty is based on a set or sets of measurements in repeatability or re-producibility conditions, and gives data about preciseness of test method, but not about trueness, because information about systematic errors during measurement process is loosen. On the other hand, type B of measurement uncer-tainty is based on deviations of separate measurements and on accuracy of particular measurement devices included in test process. Based on type B measurement uncertainty cal-culation, data about influence of particular measurements on final result can be given and critical parts of test procedure can be recognized.

measurement uncertainity; test methods; testing laboratory; building materials

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