1 {\Omega}-10 k{\Omega} high precision transportable setup to calibrate multifunction electrical instruments

TL;DR

This paper presents a portable, high-precision resistor setup for calibrating multifunction electrical instruments, featuring innovative design elements that ensure stability and low measurement uncertainty during transport and use.

Contribution

The development of a temperature-controlled, transportable resistor setup with novel oil insertion design for improved stability and low uncertainty in calibration applications.

Findings

Short and mid-term stability comparable to top commercial standards.

Transport effects do not significantly affect measurement accuracy.

Uncertainties meet calibration requirements for DMMs and MFCs.

Abstract

A temperature controlled 1 {\Omega}-10 k{\Omega} standard Resistors transportable setup was developed at National Institute of Metrological Research, (INRIM) for the calibration and adjustment of multifunction electrical instruments. The two Standards consist respectively of two 10 {\Omega} and 100 k{\Omega} parallel connected resistors nets inserted in a temperature controlled aluminium box. Novelty of the realization is the oil insertion of the 1 {\Omega} net with its internal connectors lowering the thermo-electromotive forces (emfs) effects. Short and mid-term stabilities of the setup Standards resulted on the order and in some cases better than other top level 1 {\Omega} and 10 k{\Omega} commercial Standards. The transport effect turning off the setup temperature control did not cause appreciable measurement deviations on the two Standards. The Standards uncertainties meet those requested by DMMs and MFCs manufacturers to calibrate and adjust these instruments. A test to adjust a multifunction calibrator gave satisfactory results.