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NIST Guide to the SI, Chapter 3: Other Sources of Information on the SI

3.1 Publications

Appendix C briefly describes a number of publications that deal with the SI and related topics; citations for these publications are given in Appendix D—Bibliography. Additional information about the SI is also available from the two NIST organizational units indicated in Secs. 3.2 and 3.3.

3.2 Fundamental Constants Data Center

Questions concerning the more fundamental aspects of the SI and subtle aspects of proper SI usage may be directed to:

Fundamental Constants Data Center
Physics Laboratory
National Institute of Standards and Technology
100 Bureau Drive, Stop 8420
Gaithersburg, MD 20899-8420

Telephone: (301) 975-3200
Fax: (301) 990-1350
SI Units Web Page:

3.3 Metric Program

Questions concerning Federal Government use of the SI and Federal Government policy on the use of the SI by U.S. industry and the public may be directed to:

Metric Program
Technology Services
National Institute of Standards and Technology
100 Bureau Drive, Stop 2600
Gaithersburg, MD 20899-2600

Telephone: (301) 975-4004
Fax: (301) 975-8091
Email: TheSI [at] (TheSI[at]nist[dot]gov)

Created January 28, 2016, Updated August 25, 2016