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Automated Direct Comparison of Two Cryocooled 10 Volt Programmable Josephson Voltage Standards



Alain Rufenacht, Yi-hua D. Tang, Stephane Solve, Anna E. Fox, Paul D. Dresselhaus, Charles J. Burroughs, Robert E. Schwall, Regis Chayramy, Samuel P. Benz


We have performed direct dc comparisons between two cryocooled 10 V programmable Josephson voltage standards utilizing an automated synchronization scheme for the voltage reversals, which enables the use of a high-sensitivity analog null detector on its 10 µV range. No switches or manual operations are necessary to protect the null detector from overload signals. The agreement measured between the two voltage standards at 10 V is 9 parts in 10^12 with a relative combined uncertainty of 29 pV/V (k=2). Since both systems can be operated floating from the Earth potential, various grounding configuration of the measurement circuit were investigated, allowing evaluation of the comparison result on various leakage current paths to ground. Comparing the two systems under various grounding conditions enables minimization of the leakage current errors, optimization of the system performance by revealing leakage- limiting components, and verification of key elements of the uncertainty budget for the measurement method


Digital-analog conversion, Josephson arrays, standards, superconducting integrated circuits, voltage measurement.


Rufenacht, A. , Tang, Y. , Solve, S. , Fox, A. , Dresselhaus, P. , Burroughs, C. , Schwall, R. , Chayramy, R. and Benz, S. (2018), Automated Direct Comparison of Two Cryocooled 10 Volt Programmable Josephson Voltage Standards, Metrologia, [online], (Accessed April 24, 2024)
Created July 6, 2018, Updated November 10, 2018