Uncertainty Evaluation of Flow Meter Calibration by Gravimetric Water Flow Standards at KRISS

Abstract Petrochemical and electric power plants are using flow meters, of which capacity is larger than 1000 m3/h. They require the accuracy of flow meters better than ±0.3% if the flow meters are being used for custody transfer or allocation measurement. However, the number of national metrology institutes, which can handle this issue, is very limited, including PTB (Germany), NMIJ/AIST (Japan), MIKES (Finland), CEESI-NIST (USA), and TÜV-NEL (UK). Large-capacity flow measurement standards are also needed to make better quality control for process engineering in the Republic of Korea. This study aims at establishing the water flow measurement standards up to 2000 m3/h with uncertainty better than 0.06%. How to evaluate the measurement uncertainty is discussed for establishing the large-capacity water flow standards at KRISS.