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Distributing UTC(NIST) to Industrial Time and Frequency Users



Michael A. Lombardi, Victor S. Zhang


The National Institute of Standards and Technology (NIST) maintains one of the world s most accurate and stable time scales, UTC(NIST), as well as the NIST-F1 cesium fountain, the primary frequency standard for the United States. These standards are continuously compared to other standards around the world to ensure traceability to the International System (SI) of units, and UTC(NIST) is continuously distributed to industrial and research facilities around the world through a variety of methods and mediums. The most accurate of these methods are remote calibration services that distribute UTC(NIST) to a relatively small number of paying customers. UTC(NIST) at lesser accuracy is freely distributed to many millions of users via NIST radio stations WWV/WWVH and WWVB, the Internet Time Service (ITS), the Automated Computer Time Service (ACTS), and the NIST web clock (
Proceedings Title
Proc. 2009 National Meeting on Electrical Metrology
Conference Dates
November 18-20, 2009
Conference Location


remote calibrations, time, timescale, time signals


Lombardi, M. and Zhang, V. (2009), Distributing UTC(NIST) to Industrial Time and Frequency Users, Proc. 2009 National Meeting on Electrical Metrology, Queretaro, -1, [online], (Accessed March 2, 2024)
Created November 18, 2009, Updated February 19, 2017