Improvement of leakage resistance of PJVS for NIST-4 watt balance experiment

A Programmable Josephson Voltage Standard (PJVS) system is used for the voltage measurements in the NIST-4 watt balance experiment. In order to achieve the uncertainty of voltage measurements better than 1 part in 10
⁹
, it is critical to increase the leakage resistance of the PJVS to ground. This paper describes how to modify the watt balance PJVS system to isolate the bias electronics and quantify its resistance to ground. Direct comparison between the watt balance PJVS (WPJVS) and NIST Volt Lab PJVS (VPJVS) was carried out to verify the performance of WPJVS with improved isolation resistance.