Leakage Current Effects with Programmable Josephson Voltage Standards

This work presents the results of evaluating and measuring the dc leakage effects associated with Programmable Josephson Voltage Standards (PJVS). Two types of leakage error can occur in PJVS systems. The first type involves leakage currents to Earth ground, which can result from the resistance of cable insulation and the bias electronics. The second type is related to the voltage divider effect, caused by potential leakage paths on the precision output leads. Both effects can impact the measurement accuracy of the PJVS and must be monitored regularly. We have developed assessment methods, including both manual and automated measurements, that can be applied to any disseminated PJVS systems currently in use.