Measurement science and the linking of CIPM and regional key comparisons

摘要

A generalized formalism is presented for linking a Comite International de Poids et Mesures ( CIPM) key comparison ( KC) with similar regional KCs. The mechanism proposed provides a straightforward and practical means for reporting on the equivalence of the larger ensemble of national metrology institutes resulting from the linking of a regional metrology organization KC to the CIPM KC of the same measurand. Redundancy in the linking path which results when there is more than one linking lab is exploited for testing the statistical consistency of the linking relative to the claimed uncertainties. The proposed linking procedure is described and illustrated with a real-world practical example employing extended chi-squared-like statistics. A procedure for linking in the presence of artefact drift or other parametrized corrections is outlined.