Analysis of Uncertainty in Interlaboratory Evaluations Based on the ISO Guide
.
Raghu Kacker
NIST/ITL/MCSD/MMG
Tuesday, November 27, 2001 13:00-14:00,
Room 145, NIST North (820)
Gaithersburg
Tuesday, November 27, 2001 11:00-12:00,
Room 4550
Boulder
Abstract:
A substantial diversity exists in the literature on how to analyze the
uncertainty in interlaboratory evaluations of a common measurand. The issues
include the following. What is the combined result and what uncertainty is
associated with it? What to do when the expanded uncertainty interval
associated with the combined result excludes a non-negligible fraction of the
individual laboratory results? We discuss these issues and propose a simple
approach based on the ISO Guide to determine the combined result and the
associated uncertainty so no reasonable result of measurement is excluded. We
will illustrate the proposed approach through an application to the recent
results of the international comparison of cryogenic radiometers organized by
the Consultative Committee for Photometry and Radiometry (CCPR). In
particular, we show how the proposed approach may be used to quantify the
worldwide uncertainty in cryogenic radiometry.
Contact: A. J. KearsleyNote: Visitors from outside NIST must contact
Robin Bickel; (301) 975-3668;
at least 24 hours in advance.
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