This document specifies the minimum requirements to quantify boil-off gas (BOG) consumed on liquefied natural gas (LNG) carriers for their own functions, in particular for power generation and during cargo transfer operations.

This document provides requirements for the metering of BOG and the subsequent calorific value calculations, which can be taken into account when the energy transferred during cargo transfer is determined. This document also gives performance requirements and calibration of the elements included in the BOG measurement system.

This document, with some modifications, can also be applied to the measurement of BOG consumed by LNG carriers at sea.