Uncertainty Evaluation in a Two-Terminal Cryogenic Current Comparator

We present an uncertainty evaluation of a new cryogenic current comparator (CCC) bridge that is designed to compare two-terminal 1 and 10 MOmega standard resistors with the quantized Hall resistance (QHR) and scale from these decade values to other decade values between 10 kOmega and 1 GOmega. Use of the bridge over a wide range of resistance values results in a spectrum of dominant contributions to the uncertainty budget, and this analysis helps determine the optimum parameters of the measurements. Our theoretical analysis is compared with experimental data.