VSL releases first results of flow meters calibrated in cryogenic conditions at its LNG test facility

VSL’s LNG Research and Calibration facility has delivered its first SI-traceable LNG flow meter calibration results. A total of six flow meters from five leading flow meter manufacturers were calibrated in the test facility using liquid nitrogen. Apart from the calibrations themselves, effects of upstream flow disturbances and of insulation of the flow meters were investigated. The results are summarized in a publicly available paper which can be downloaded here.


VSL’s LNG Research and Calibration facility in the port of Rotterdam, the Netherlands.

These results mark a big step in the development of the facility towards its ultimate goal of performing midscale (up to 1000 m3/h) LNG flow and composition calibrations. VSL is proud of these achievements and thanks everyone who has contributed to the results.

In the LNG industry it is customary to calibrate custody transfer flow meters at ambient conditions with water as an alternative liquid for LNG. Correction equations derived from literature liquid nitrogen data are applied to compensate for the differences between water and LNG conditions. The reason for calibrating using water at ambient conditions is the lack of facilities that enable research into meter performance and calibrations of meters under cryogenic conditions (at temperatures as low as -190 °C) and at the proper scale. In 2019 VSL completed the construction and commissioning of its LNG Research and Calibration facility. The first set of ‘real’ calibrations consisted of a program of Coriolis and Ultrasonic flow meters using liquid nitrogen. Many partners from industry, academia, and the metrological community contributed to the program. The calibrations were performed as part of the EMPIR project Metrological support for LNG and LBG as transport fuel.

The calibrations showed good repeatability and typical flow meter curves. This demonstrates the facility’s potential of calibrations at sufficiently low SI-traceable measurement uncertainty. These results enable systematic research into LNG metering and open the door to the development and calibration of flow meters suitable for measuring LNG. Meter manufacturers can use the facility to prove flow meter performance and the corresponding measurement uncertainty under cryogenic circumstances.

Menne Schakel, project coordinator of Metrological support for LNG and LBG as transport fuel (16ENG09, LNGIII) is proud: “The successful completion of the first SI-traceable calibration program, using liquid nitrogen in the LNG Research and Calibration facility, marks an important milestone in developing the metrological infrastructure for LNG custody transfer. The results on practical issues, such as flow disturbances and the insulation of the LNG flow meter, provide valuable information for day-to-day application of LNG to trucks and ships. The facility will enables LNG meter manufacturers, LNG end-users, and the metrological and scientific communities to gain confidence in LNG trade, by demonstrating the suitability of LNG meters and complete measuring systems for requirements set by the industry. The facility will play a key role in the large-scale application of LNG in the energy transition, as a clean alternative to fossil fuels.”