Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

CIPM Mutual Recognition Arrangement

NIST is a signatory to the International Committee on Weights and Measures (CIPM) Mutual recognition Arrangement (MRA). NIST calibration and measurement capabilities (CMCs) under the MRA are reported in the MRA database in Appendix C. In some cases, the uncertainties provided by NIST for services listed in NIST Special Publication 250 may be smaller than those for the CMCs currently listed for NIST in the MRA database, for example, because of the time lag involved in having new CMCs included in the database. The NIST Division technical contacts listed in the SP 250 for each service can provide up–to–date information on the CMC status.


Created January 7, 2010, Updated November 15, 2019