Interlaboratory studies have long been used to ensure measurement capability for commerce since accurate measurements are necessary for assessing product specifications. For this reason design and analysis of interlaboratory studies have been an important part of the ITL Statistical Engineering Division's (ITL/SED) work for many years. Recently, however, a new type of interlaboratory study, known as a key comparison, has taken a critical new place in the NIST mission. In the last year, key comparisons, international interlaboratory studies for comparing measurement results between leading National Metrology Institutes (NMI's), have provided many new opportunities for ITL/SED to collaborate with scientists across NIST. The impetus for these new opportunities is a Mutual Recognition Arrangement (MRA) signed by the NMI's belonging to the International Committee for Weights and Measures (CIPM) "to establish the degree of equivalence of national measurement standards maintained by NMI's, to provide for the mutual recognition of calibration and measurement certificates issued by NMI's, [and] thereby to provide governments and other parties with a secure technical foundation for wider agreements related to international trade, commerce and regulatory affairs."
Key comparisons serve as the technical basis for the MRA and must therefore accurately reflect the true relationships between measurement systems maintained by NMI's belonging to the CIPM. The results of key comparisons must also be extensible to members of Regional Metrology Organizations (RMO's) to maximize recognition of measurement capabilities that exist in other metrology laboratories around the world.
ITL/SED contributions to interlaboratory studies and key comparisons include the following.
The contributions of collaborators include the following.