This International Standard provides the means for energy determination of natural gas by measurement or by
calculation, and describes the related techniques and measures that are necessary to take. The calculation of
thermal energy is based on the separate measurement of the quantity, either by mass or by volume, of gas
transferred and its measured or calculated calorific value. The general means of calculating uncertainties are
also given.
Only systems currently in use are described.
This International Standard applies to any gas-measuring station from domestic to very large high-pressure
transmission.
New techniques are not excluded provided their proven performance is equivalent to, or better than, that of
those techniques referred to in this International Standard.
Gas-measuring systems are not the subject of this International Standard.