BIROn - Birkbeck Institutional Research Online

    A properly developed consensus from a proficiency test is, for all practical purposes, interchangeable with a certified value for a matrix reference material derived from an interlaboratory comparison

    Thompson, Michael (2018) A properly developed consensus from a proficiency test is, for all practical purposes, interchangeable with a certified value for a matrix reference material derived from an interlaboratory comparison. Geostandards and Geoanalytical Research 42 (1), pp. 91-96. ISSN 1639-4488.

    Full text not available from this repository.

    Abstract

    A properly developed consensus from a proficiency test is, for all practical purposes, interchangeable with a certified value derived from an interlaboratory comparison. But some scientists have doubts about the metrological status of such values. In particular, the materials are not regarded as equivalent to certified reference materials (CRM) because of a lack of traceability of the consensus value. However, the detailed considerations in this study show that such a distinction is without foundation. The following issues are addressed. (a) Misgivings about the traceability of an interlaboratory consensus are found to be insubstantial because chemical measurements are hardly ever fully traceable. (b) Reproducibility (i.e., interlaboratory) conditions account for all sources of variation in results other than long-term stability, so lead to a valid estimate of uncertainty. (c) Certification of a reference material according to ISO procedures is homologous with a proficiency test and no more secure against bias in the characterised value and its standard error. In particular, residual (common) bias cannot be fully addressed in either approach. (d) A consensus in itself attests to a valid outcome. (e) Proficiency test providers have access to a powerful method of monitoring long-term stability that is denied to CRM producers.

    Metadata

    Item Type: Article
    School: School of Science > Biological Sciences
    Depositing User: Administrator
    Date Deposited: 08 Dec 2017 15:05
    Last Modified: 27 Jun 2018 13:51
    URI: https://eprints.bbk.ac.uk/id/eprint/20570

    Statistics

    Downloads
    Activity Overview
    0Downloads
    119Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item