Re-evaluation of uncertainty for calibration of $100$ M$\Omega$ and $1$ G$\Omega$ resistors at NPL

TL;DR

This paper re-evaluates the uncertainty in calibrating high-value resistors at NPL, significantly reducing the estimated uncertainties and enabling more precise measurements of quantum current standards.

Contribution

The study provides a revised uncertainty assessment for high-resistance resistor calibration, improving the accuracy of quantum current measurements.

Findings

Combined uncertainties reduced to ~0.1 μΩ/Ω

Supports measurement of single electron pump currents with uncertainties of a few parts in 10^7

Revised uncertainties are smaller than previous CMC entries

Abstract

The uncertainty for calibrating $100$ M$\Omega$ and $1$ G$\Omega$ resistors using the NPL high-resistance CCC bridge has been re-evaluated, resulting in combined uncertainties of $\sim 0.1$ $\mu\Omega/ \Omega$, considerably smaller than the CMC entries of $0.4$ $\mu\Omega/ \Omega$ and $1.6$ $\mu\Omega/ \Omega$ respectively. This re-evaluation supports measurement of single electron pump currents with combined uncertainties of a few parts in $10^7$.