1.1 This test method covers the estimation of the net heat of combustion (specific energy) at constant pressure in SI units, megajoules per kilogram, from the fuel density, sulfur, and hydrogen content.

1.2 This test method is purely empirical, and it is applicable only to liquid hydrocarbon fuels derived by normal refining processes from conventional crude oil that conform to the requirements of specifications for aviation turbine fuels of limited boiling ranges and compositions, as described in Note 1 and permitted by each specification.

Note 1--The estimation of the heat of combustion of a hydrocarbon fuel from its hydrogen content, density, and sulfur is justifiable only when the fuel belongs to a well-defined class for which a relationship between these quantities has been derived from accurate experimental measurements on representative samples of that class. Even in this class, the possibility that the estimates can be in error by large amounts for individual fuels should be recognized. The classes of fuels used to establish the correclation presented in this test method are represented by the following specifications:

1.3 The heat of combustion can also be estimated by Test Methods D1405, D3338, and D4529.