Second Round of Comparison Tests for High-Current Shunts in High-Power Laboratories in Asia and North America with an STL Reference Shunt

Abstract

To establish traceability for high-current measurements, comparison tests of high-current shunts in high-power laboratories have been performed with short-circuit testing liaison (STL) reference shunts since 2005. The concept of the project involves providing only STL traceable shunts and leaving the remaining components needed to form a complete reference-measuring system to the laboratories themselves. Two STL reference shunts (hereinafter called reference shunts) were manufactured, one of which was used in Asia and the other in Europe and Africa. The reference shunts exhibit an rms value of 140 kA symmetrical current, and an asymmetrical peak current of 350 kA. The first round of the comparison tests finished in 2009, and the second round started in 2012. Before starting the second round of comparison tests, the two reference shunts were compared at the CRIEPI high-power testing laboratory in Japan in October 2011. The test results of the inter-comparison tests showed that the two reference shunts qualified as references. From 2012 to 2018, nineteen laboratories in Asia and North America attended comparison tests using the reference shunt for Asia and provided their test data for this paper. In this paper, we describe the comparison test results of shunts in high-power laboratories in Asia and North America in the second round. The test results showed that the shunts tested for the comparison tests performed well and most of the differences in the scale factor with the power frequency current between the reference shunt and those tested in participating laboratories were small.