Title :
Comparison of two Josephson array voltage standard systems using a set of Zener references
Author :
Tang, Yi-hua ; Steiner, Richard ; Sims, June
Author_Institution :
Nat. Inst. of Stand. & Technol., Gaithersburg, MD, USA
fDate :
4/1/1999 12:00:00 AM
Abstract :
It is possible to compare Josephson-array voltage systems to parts in 109 via multi-Zener reference interchanges and ultra-low thermal-emf switching. These techniques were used to achieve a Type A uncertainty of 6 nV/V (k=2) at the 1.018 V level, and to establish that the agreement between the two systems fell within the estimated 4 nV/V Type B relative uncertainty (k=2). The method is useful in checking system operation under normal measurement configurations and programmed control. Data also indicated that thermal-emfs greater than 25 nV have fluctuations that are not perfectly cancelled by either of the two differing measurement algorithms
Keywords :
Josephson effect; Zener diodes; measurement standards; measurement uncertainty; superconducting arrays; superconducting junction devices; voltage measurement; 1.018 V; Josephson array; Type A uncertainty; Type B relative uncertainty; measurement algorithms; multi-Zener reference interchanges; normal measurement configurations; programmed control; system operation; ultra-low thermal-emf switching; voltage standard systems; Calibration; Control systems; Electric variables measurement; Fluctuations; Instruments; Josephson junctions; Switches; Thermal variables measurement; Voltage measurement; Voltmeters;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
