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The Ampere and Electrical Standards



Randolph Elmquist, Marvin E. Cage, Yi-hua D. Tang, Anne-Marie Jeffery, Joseph R. Kinard Jr., Ronald F. Dziuba, Nile M. Oldham, Edwin R. Williams


This paper describes some of the major contributions to metrology and physics made by the NIST Electricity Division, which has existed since 1901. It was one of the six original divisions of the National Bureau of Standards. The Electricity Division provides dc and low-frequency calibrations for industrial, scientific and research organizations, and conducts research on topics related to electrical metrology and fundamental constants. The early work of the Electricity Division staff included the development of precision standards, such as Rosa and Thomas standard resistors and the ac-dc thermal converter, and contributions to the international system of units and the transition to absolute units based on fundamental principles and physical and dimensional measurements. NIST research has helped to develop and refine electrical standards using the quantum Hall effect and the Josephson effect, which are both based on quantum physics. Four projects, covering a number of voltage and impedance measurements, are described in detail. Several other areas of current research at NIST are described, including the use of the Internet for international compatibility in metrology, determination of the fine-structure and Planck constants, and construction of the electronic kilogram.
Journal of Research (NIST JRES) -


calibration, electrical engineering, Internet, Josephson arrays, measurement units, resistance measurements


Elmquist, R. , Cage, M. , Tang, Y. , Jeffery, A. , Kinard Jr., J. , Dziuba, R. , Oldham, N. and Williams, E. (2001), The Ampere and Electrical Standards, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 21, 2024)


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Created December 31, 2000, Updated October 12, 2021