The comparison of the gas flow secondary standard facilities at high pressure

Abstract

The first formal comparison was organized in China for the purpose of determination of the degree of equivalence of the gas flow secondary standard facilities during 2016~2020. There were 4 participants from China, and PTB was invited as the link lab to connect this comparison with the serial key comparisons of CCM.FF.K5. Based on the flow range of the existing secondary standard facilities of participating laboratories, 3 turbine flow meters were used as transfer standards. Totally 298 sets of measured data were obtained with Reynolds number range of (6.3×10 4 ~1.4×10 7 ). Results of all participants were considered for the determination of the reference value and the uncertainty of the reference value. The operation conditions were represented by the Reynold number, while the measured value was represented by the relative error of the meter e in (%). The fitted curve based on the relationship between e and the Reynolds number for each single meter was obtained. The degree of equivalence of En was finally evaluated. Among all 298 sets of measured results, there were 282 sets of results with En≤1, while there were 9 sets of results with 1< En≤1.2.