Address:
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#321, Sec. 2, Kuang Fu Rd.,
Hsinchu, Taiwan, 300, Taiwan
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Abstract:
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Inter-Comparability Tests of Gas Flow Measurement Standards Speaker: Jiunn-Haur Shaw Center for Measurement Standards/ITRI #30 Ta Shueh Road, Hsinchu, Taiwan, ROC Tel:886-3-5741200, fax:886-3-5710335 Jiunn-haur.shaw@itri.org.tw Author(s):Jiunn-Haur SHAW*, Wen-Ti LIN*, Jian WU **, Chye Tiong WOON** * Center for Measurement Standards, ITRI, Taiwan, ROC **National Measurement Center, SPRING, Singapore Abstract This paper describes the proficiency evaluation of the low-pressure air-flow national standards at Center for Measurement Standards (CMS). Three sets of gas flow standard facility, namely, a Brooks five-tube piston prover, a 60liter small bell prover and a 600liter large bell prover, were verified and quantified of those uncertainty sources based on the ISO Guide to the Expression of Uncertainty in Measurement (GUM). The expanded uncertainties for mass flow rate measurement are 0.1%, 0.19%, and 0.14%, for piston, small bell and large bell, respectively. In order to validate the claimed uncertainties and to check the measurement consistency among these standards during calibration services, three different sizes of Laminar Flow Elements (LFE) and two Critical Flow Venturies (CFV) were taken as transfer standards for comparison tests. The En value, namely the difference of measurement errors of unit under test (UUT) from two standard systems against the root-sum-squares of systems and individual UUT measurement uncertainties, is taken as check parameter. Test results show that all En values lie within 0.63, indicating the measurement consistency among various flow standards. Furthermore, an inter-comparison test using two LFE was conducted between CMS and National Measurement Center/SPRING of Singapore. Within the test flow rate of 0.2liter/min to 24liter/min, the overall measurement difference is within 0.2% and the En value lie within 0.8, showing the measurement comparability between the two National Measurement Institutes.
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