Typical calibration accuracy (direct comparison to a second Josephson Voltage Standard)

± 4 nV @ 10 V
ΔV/V_{10 V} = 4×10^-10

Typical calibration accuracy of secondary voltage standards (limited by the noise of the secondary voltage standard)

± 20 nV @ 1V
ΔV/V_{1 V} = 2×10^-8

± 100 nV @ 10 V
ΔV/V_{10 V} = 1×10^-8

Thermal voltage of wires and reversal switch

< 10 nV @ all 3 channels

Typical gain factor g of external voltmeter (depends on the type of voltmeter)

Δg/g < 3×10^-7  

The measured voltage difference corresponds to an accuracy of 7×10^-11 with a measurement uncertainty of 3.4×10^-10.