DocumentCode
1296433
Title
Monitoring the U.S. legal unit of resistance via the quantum Hall effect
Author
Cage, Marvin E. ; Dziuba, Ronald F. ; Field, Bruce F. ; Kiess, Thomas E. ; Van Degrift, Craig T.
Author_Institution
Electricity Division, National Bureau of Standards, Gaithersburg, MD 20899
Issue
2
fYear
1987
fDate
6/1/1987 12:00:00 AM
Firstpage
222
Lastpage
225
Abstract
The quantum Hall effect is being used to monitor the resistances of the five 1-Ω Thomas-type resistors which define the U.S. legal unit of resistance, the ohm maintained at the National Bureau of Standards (ΩNBS ). Typically, the total one-standard-deviation (1σ) accuracy for the transfer between three different GaAs quantum Hall devices and the five 1-Ω resistors is ±0.05 ppm. Measurements to date provide the first direct evidence that the value of ΩNBS is decreasing by about (0.05 ± 0.02) ppm per year.
Keywords
Electrical resistance measurement; Measurement uncertainty; NIST; Resistance; Resistors; Temperature measurement; Uncertainty;
fLanguage
English
Journal_Title
Instrumentation and Measurement, IEEE Transactions on
Publisher
ieee
ISSN
0018-9456
Type
jour
DOI
10.1109/TIM.1987.6312673
Filename
6312673
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