Design of a cryogenic liquid flowmeter calibration system using liquid nitrogen

In line with the recent global trend towards environmental sustainability, there has been an increase in the use of cryogenic liquefied gases such as liquefied natural gas and liquid hydrogen. The need to calibrate liquid flowmeters under cryogenic conditions has emerged to reduce measurement uncertainty in trading amounts of these cryogenic liquids. To calibrate liquid flowmeters under cryogenic conditions, the Korea Research Institute of Standards and Science (KRISS) is designing a standard system for measuring cryogenic liquid flow, utilizing liquid nitrogen as the working fluid. This system applies a gravimetric method traceable to primary standards of SI units and introduces a dynamic flow measurement method for stable measurements in cryogenic environments. This study introduces the design and implementation progress of the ongoing cryogenic liquid flow measurement standard system at around 77K and a flowrate range from 5 to 20 m 3 /hr.