The impact of measurement uncertainty on the producer’s and user’s risks, on classification and conformity assessment: an example based on tests on some construction products

摘要

The reliability of test results and subsequent classification statements or product certification depend on the variability of the product’s properties and on the validity of the test procedures used. With an emphasis on measurement uncertainty, producer’s and user’s risks as well as probabilities of conformance, conformity and classification are calculated exemplarily for two requirements for mineral aggregates used in construction. An important methodological basis is an international draft document on measurement uncertainty in conformity assessment. The mathematical instruments given are applied and further developed to a risk scenario for product classification. The results from a classification point of view show that the reliability of test results for acid-soluble sulphates is mostly acceptable and both the producer’s and user’s risks are quite small. In contrast, the magnesium sulphate index test produces results which are hardly usable for classification and certification purposes or for risk management in production. Product certification bodies should generally have an appropriate approach when dealing with results where precision data are poor.