Resistance Scaling From 10 ${\rm k}\Omega$ Up to 100 ${\rm T}\Omega$ With New Designs of Hamon Transfer Devices

Abstract

This paper describes the realization of a new system for resistance scaling from 10 ${\rm k}\Omega$ to 100 ${\rm T}\Omega$ . The resistance unit has been transferred from the quantum hall resistance (QHR) primary resistance standard to the resistance standard with a nominal value of 10 ${\rm k}\Omega$ by a cryogenic current comparator. For further transfer of the resistance unit from 10 ${\rm k}\Omega$ to 100 ${\rm T}\Omega$ , Hamon transfer devices (Hamon networks) are used. For its complete realization five devices have been developed: 10–100–1000 ${\rm k}\Omega$ , 1–10–100 ${\rm M}\Omega$ , 0.1–1–10 ${\rm G}\Omega$ , 10–100–1000 ${\rm G}\Omega$ , and 1–10–100 ${\rm T}\Omega$ . The first two devices have a single insulation, and the next three have a double isolation. In the transfer devices with the double insulation, triax-type connectors are used. All transfer devices have individual temperature stabilization within ${\pm}{\rm 0.01}^{\circ}{\rm C}$ . In the paper, the factors influencing device accuracy have been described. The insulation leakage is recognized, and the error caused by it is calculated. The guarding network for the new design of Hamon transfer devices is presented. Voltage coefficients of resistance and settling times of resistors used in these devices have been determined and discussed. Uncertainties for the Hamon transfer devices ratios have been calculated. Calibration results have been presented. The developed system is currently tested in the Central Office of Measures in Poland.