This International Standard describes a procedure for the estimation of the net specific energy of aviation turbine
fuels using hydrogen content data. It is not applicable to pure hydrocarbons.
The method is purely empirical and is applicable only to liquid hydrocarbon fuels derived by normal refining
processes from conventional crude oil which conform to the requirements of specifications for aircraft turbine and
jet engine fuels of limited boiling ranges and compositions.
NOTE 1 The method is intended for use as a guide in cases where an experimental determination of net specific energy is
not available and cannot be made conveniently, and where an estimate is considered satisfactory for specifications and similar
purposes. It is not intended that estimated values of the net specific energy be used in place of experimentally determined
NOTE 2 The estimation of the net specific energy of hydrocarbon fuel from its sulfur content, hydrogen content and density is
justifiable only when the fuel belongs to a well-defined class for which a relationship between net specific energy and sulfur
content, hydrogen content and density has been derived from accurate experimental measurements on representative samples
of this class. Even in this class, the possibility that the estimates can be in error by large amounts for individual fuels must be
NOTE 3 The fuels used to establish the correlation presented in this International Standard are defined in annex A.