ASTM D6446 Estimation of Net Heat of Combustion of Aviation Fuels
ASTM D6446 Standard Test Method for Estimation of Net Heat of Combustion (Specific Energy) of Aviation Fuels
7. Report
7.1 Report the result for the net heat of combustion Qp in MJ/kg to the nearest 0.01 MJ/kg.

7.2 Report the result for the volumetric net heat of combustion Qv in MJ/m3 to the nearest 10 MJ/m3.

8. Precision and Bias
8.1 Precision - The following criteria shall be used for judging the acceptability of estimated heat of combustion results when using data on the hydrogen content, the density, and the sulfur content of a fuel determined by Test Methods D3701, D1298, and D129, respectively (see Note 3).

NOTE 3 - The correlation between net heat of combustion and the hydrogen content, the density and the sulfur content defined in Eq 1 was developed based on measured data by Test Methodds D3701, D1298, and D129, respectively. Use of alternative test methods having a greater or lesser precision will have a like trend on the precision of the estimated net heart of combustion.

8.1.1 Repeatability - The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the following values in only one case in twenty:
Repeatability 0.05 MJ/kg

8.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the following values in only one case in twenty:
Reproducibility 0.06 MJ/kg

NOTE 4 - As a guide, an estimate on a volume basis for a fuel with a density of 810 kg/m3, rounded to the nearest 10 MJ/kg is:
Repeatability: 40 MJ/m3
Reproducibility: 50 MJ/m3

8.2 Bias - No general statement is made on bias for the test method since the data used to determine the correlation cannot be compared with accepted reference materials.

9. Keywords
9.1 aviation fuels; energy content; heat of combustion; heating tests; net heat of combustion; specific energy