Precision AC-DC Difference Measurement System Based on a Programmable Josephson Voltage Standard

A system designed for precision measurement of ac-dc difference of thermal voltage converters in terms of a programmable Josephson voltage standard is under development at the National Measurement Institute, Australia, in collaboration with the National Institute of Advanced Industrial Science and Technology, Japan. The agreement between the new system and calculable thermal converters is presently better than 0.5 μV/V at frequencies up to 40 Hz and voltages up to 0.75 V.