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Realizing the SI in the 21st Century at NIST



K B. Gebbie


As it embarks on its second 100 years, the National Institute of Standards and Technology is developing new approaches to realizing and disseminating the SI. Efforts to improve the realization of the second include development of a laser-cooled cesium atomic clock in space to take advantage of the long observation times provided by the micro-gravity environment, development of an optical atomic clock based on a single trapped 199 Hg+ ion to take advantage of the higher operating frequency, and development of a chip-scale atomic clock to provide ultra-miniaturized, ultra-low-power time and frequency references for measurement instrumentation. New directions in photometry and radiometry include application of detector-based standards to solid-state light sources, and a space-based calibration program to assure long-term accuracy of instrumentation for remote sensing and environmental monitoring. To realize the SI unit of voltage and provide and alternative definition of the unit of mass, NIST is pursuing a watt balance experiment, which compares mechanical and electrical power in terms of fundamental quantum phenomena. At the same time, new computing and networking technologies are enabling the delivery of measurement services to remote industry, government and university laboratories. This talk will discuss these programs as well as new directions in nanotechnology, biotechnology, and quantum information.
International Conference on Metrology


atomic clock, biotechnology, mass, nanotechnology, photometry, quantum information, radiometry, SI, voltage


Gebbie, K. (2008), Realizing the SI in the 21st Century at NIST, International Conference on Metrology (Accessed June 18, 2024)


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Created October 16, 2008