Title :
A result from the NIST watt balance and an analysis of uncertainties
Author :
Steiner, Richard L. ; Newell, David B. ; Williams, Edwin R.
Author_Institution :
Div. of Electr., Nat. Inst. of Stand. & Technol., Gaithersburg, MD, USA
fDate :
4/1/1999 12:00:00 AM
Abstract :
An improved determination of the ratio of power, measured in terms of the Josephson and quantum Hall effects, and also the meter, kilogram, and second, has been completed. The result is expressed as: W90 /W=1+(8±87)×10-9. This is an order of magnitude improvement from the last NIST (formerly NBS) determination. The Type A relative standard uncertainty (statistical) is 30 nW/W, and the Type B relative standard uncertainty is 82 nW/W. Type B uncertainty components are listed and discussed within the context of experimental procedure descriptions. Improvements for the next version of this experiment are also mentioned
Keywords :
Josephson effect; measurement standards; measurement uncertainty; power measurement; quantum Hall effect; units (measurement); NIST watt balance; SI power units; SI watt measurement; force mode; measurement units; uncertainties analysis; velocity mode; watt ratio measurement; Gravity; Hall effect; Magnetic field measurement; Measurement units; NIST; Power measurement; Superconducting coils; Time measurement; Uncertainty; Voltage;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
