Assessment of the homogeneity of repackaged batches of reference materials

Johanna Abella, Andrea Mojica, Diego A. Ahumada

Abstract

During 2020, the National Metrology Institute of Colombia, organized one proficiency testing (PT) for the quantification of elements in water. In the PT, external reference values were used instead of consensus values derived from the participants' results. The test material used in the PT was a certified reference material from another National Metrology Institute. To maintain the confidentiality of certified values, it was necessary to carry out a repackaging process. Therefore, in this work are presented the results of several studies that sought to establish the best mechanism to carry out this repackaging process. Among the investigations carried out, were evaluated: (i) kind of sampling and (ii) the number of bottles to assess the homogeneity of the new batch. The homogeneity uncertainty was estimated based on the number of bottles and depending on the type of sampling. From the results, it was identified that (i) most of the elements evaluated, the smallest contribution to the uncertainty is obtained when every two units are systematically sampled, and (ii) the estimation of uncertainty due to homogeneity causes an overestimation up to three times when the number of bottles is varied.

Keywords

Assessment of homogeneity, Uncertainty, Proficiency testing

Download

IMEKO-TC10-2020-016.pdf

DOI

-

IMEKO TC

TC10 - Measurement for Diagnostics, Optimization and Control

Back to the proceedings