ASTM D4529 Test Method for Estimation of Net Heat of Combustion of Aviation Fuels
7. Report
7.1 Report the following information:
7.1.1 Report the result for the net heat of combustion Qp in MJ kg(-1) to the nearest 0.001.
7.1.2 Report the result for the volumetric net heat of combustion qp in MJ L(-1) to the nearest 0.001, if required.
8. Precision and Bias
8.1 Precision - The following criteria shall be used for judging the acceptability of estimated heat of combustion results (95 % confidence) when using data on the aniline point temperature, the density, and the sulfur content of a fuel determined by Test Methods D611, D1298, and D129, respectively (Note 5):
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 only in one case in twenty:
Repeatability: 0.012 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 only in one case in twenty:
Reproducibility: 0.035 MJ/kg
NOTE 5 - Use of fuel property data obtained with greater or lesser precision than that of the test methods indicated will have a like trend on the precision of the predicted heat of combustion.
NOTE 6 - As a guide, an estimate of the precision on a volume basis calculated for a fuel with a density of 810.0 kg/m3 is as follows:
Repeatability: 9.7 MJ/m3
Reproducibility: 28 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 fuel; gross heat of combustion; heat energy; heat of combustion; heating tests; net heat of combustion
