Algorithms for Homogeneity Testing of Reference Materials of Dispersed and Solid Materials

Production, characterization and certification of reference materials (RMs) are key activities in ensuring the metrological traceability of measurement results in various industries. One of the sources of RM uncertainty is the standard uncertainty due to heterogeneity. Estimation of the standard uncertainty is based on the analysis-of-variance method in accordance with GOST 8.531-2002, ISO Guide 35:2017.

The main difference between the developed algorithms and ISO Guide 35:2017 is the elaboration of specific algorithms suitable for calculation and automation, the main difference from GOST 8.531-2002 is the updating of the calculation of the standard uncertainty due to heterogeneity when it is comparable to the standard measurement uncertainty of type A. The developed algorithms have been tested on various examples, and their applicability has been proven on model data.

The aim of the study was to develop algorithms for calculating the standard uncertainty due to heterogeneity of the RM for the composition and properties of dispersed and solid materials.

The objectives of the study were to analyze the algorithms set forth in GOST 8.531-2002 and ISO Guide 35:2017, and to develop and test new algorithms for calculating the standard uncertainty due to heterogeneity based on these algorithms.

The research results have shown that it is more efficient to use the approach set out in ISO Guide 35:2017 to estimate the uncertainty due to heterogeneity, modernized and taking into account the mass of the smallest representative sample. Separately, it should be noted that the developed algorithm is applicable both for studying the indicators of the composition, and properties of solid and liquid substances, and materials.

Thus, the updated algorithms will be used in the revision of GOST 8.531-2002 to harmonize GOST 8.531-2002 and ISO Guide 35:2017, as well as to increase confidence in the results of determining the metrological characteristics of RMs in Russia and ensure the uniformity of measurements at the international level.

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