This document specifies the metrological and technical requirements for flowmeters intended to be
used for the dynamic measurement of liquefied natural gas (LNG) and other refrigerated hydrocarbon fluids. For LNG static volume measurement used in custody transfer, see ISO 10976.
This document sets the best practice for the proper selection and installation of flowmeters in cryogenic applications and identifies the specific issues that can affect the performance of the flowmeter in use.
Moreover, it offers a calibration guideline for laboratory and on-site conditions (mass or volume) by
either using LNG or other reference fluids. The choice of calibration fluid will depend on the capabilities of the available flow calibration facilities and the ability to achieve the required overall measurement uncertainty demanded by the intended application.
This document is applicable, but is not limited, to the use of Coriolis and ultrasonic flowmeters for
dynamic measurements of LNG.
In principle, LNG and other refrigerated liquid hydrocarbons are considered in this document.
Recommendations in this document are based on the available test results with LNG. These results are probably applicable to other cryogenic fluids.st edition 2020-02 Refrigerated hydrocarbon fluids？—？Dynamic？measurement？—？ Requirements？and？guidelines？for？ the？calibration？and？installation？of？ flowmeters？used？for？liquefied？natural？ gas？(LNG)？and？other？refrigerated？ hydrocarbon？fluids Hydrocarbures liquides réfrigérés — Mesurage dynamique — Exigences et lignes directrices pour l’étalonnage et l’installation de débitmètres utilisés pour le gaz naturel liquéfié (GNL) et autres hydrocarbures liquides réfrigérés Reference number ISO 21903: