Fig. 3: Robustness tests of the PQCG accuracy.
From: A primary quantum current standard based on the Josephson and the quantum Hall effects
a Relative deviations, ΔI/I, at 57.42201056 μA measured with n1 = 4096 for I+, I− and I± protocols, mean value of I+ and I− results (open circle). Errors bars corresponds to combined uncertainties (see Uncertainties section in Methods). b Relative current shift from a reference value Iref, in back and forth measurements testing the effectiveness of the multiple connection (data extracted from Fig. 2e (see Combined results section in “Methods”) at 45.94 μA): measurements using the double connection with the 2nd order correction (α2) applied, using the triple connection with 50 Ω inserted in the first connection with third order correction α3 applied. The results are consistent within the Type A standard uncertainty. This confirms the accuracy of the cable corrections when applied and the efficiency of the triple connection against large cable resistance value. c Series of ΔI/I measurements carried out at 43.06650792 μA for I±, I+ and I− measurement protocols using a second PJVS1 configuration with n1 = 1920 and G = N1/N2 = 160/80. Errors bars corresponds to uA uncertainties. Discrepancies are within less than two parts in 108. This demonstrates that the PQCG can be accurate within this uncertainty even though the biasing scheme is less robust with respect to trapping magnetic flux (see Quantum devices section in Methods).
