Information about the International Comparisons Database

The International Comparisons Database (ICDB) provides access to results of comparisons of National Metrology Institute (NMI) measurements and standards. The ICDB serves the U.S. and the Inter-American System of Metrology (SIM) with information based on Appendices B and D of the Comité International des Poids et Mesures (CIPM) Mutual Recognition Arrangement (MRA). The official source of the data is The BIPM key comparison database. The National Institute of Standards and Technology (NIST) signed the CIPM MRA at a meeting of directors of NMIs on October 14, 1999 in Paris during the 21st quadrennial meeting of the General Conference on Weights and Measures. Files related to the measurement and calibration capabilities of the NMIs, referred to as Appendix C in the CIPM MRA, can now be downloaded from this site. Eventually, the records in these files will be added to the database so that users can search for specific NMI capabilities.

This version of the database contains the key and supplementary comparisons identified by the CIPM and carried out by the Consultative Committees, the BIPM, and the Regional Metrology Organizations. For comparisons that have been competed and results submitted, users can query the database for these results and for the degree of equivalence between any two sets of results or between a set of results and the comparison reference value.

The official source of the data is The BIPM key comparison database.

If you have any questions or comments, please send email to icdb@nist.gov.