منابع مشابه
The NIST Length Scale Interferometer
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 The National Institute of Standards and Technology (NIST) interferometer for measuring graduated length scales has been in use since 1965. It was developed in response to the redefinition of the meter in 1960 from the prototype platinum-iridium bar to the wavelength of light. The history of the interferometer is recalle...
متن کاملErratum: The NIST Length Scale Interferometer
[This corrects the article on p. 225 in vol. 104.].
متن کاملThe NIST Detector-Based Luminous Intensity Scale
The Système International des Unités (SI) base unit for photometry, the candela, has been realized by using absolute detectors rather than absolute sources. This change in method permits luminous intensity calibrations of standard lamps to be carried out with a relative expanded uncertainty (coverage factor k = 2, and thus a 2 standard deviation estimate) of 0.46 %, almost a factor-of-two impro...
متن کاملLength and Dimensional Measurements at NIST
This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen...
متن کاملChip - Scale Atomic Clocks at NIST
We describe recent efforts to develop microfabricated atomic frequency references capable of supporting a wide variety of commercial and military systems such as global positioning and wireless communication. These devices are anticipated to eventually have a volume of 1 cm, dissipate less than 30 mW of electrical power and maintain a fractional frequency stability better than 10 over one hour....
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Research of the National Institute of Standards and Technology
سال: 1999
ISSN: 1044-677X
DOI: 10.6028/jres.104.017