A Practical Microvolt Josephson Voltage Standard for Nanovoltmeter Measurement Based on Dual-Channel Josephson Junction Array

This paper describes the application of a microvolt Josephson voltage standard based on a dual-channel Josephson junction array developed at NIM. Using the microvolt Josephson voltage standard, DC voltage measurements ranging from $1\ \mu \mathrm{V}$ to $20\ \ \mu \mathrm{V}$ have been realized. And two different types of nanovoltmeters have been calibrated for non-linearity on $6\ \mu \mathrm{V}$ and $20\ \mu \mathrm{V}$ ranges. Results have demonstrated that the latest developed microvolt Josephson voltage standard is practical and can meet the requirement of low-level DC measurements.