up of vapors and eliminate all sources of ignition, especially nonexplosion-proof electrical apparatus and
heaters. Avoid breathing of vapor or spray mist. Avoid prolonged or repeated skin contact.
Environmental precautions for this test method are to clean up all spills immediately. Dispose of
hazardous materials and hazardous waste IAW laboratory SOP. Report all hazardous material and
hazardous waste spills immediately. Be familiar with and know the location of MSDS for all hazardous
materials present in the workplace.
Apparatus for this test method consists of smoke point lamp, wick, and pipettes or burettes.
Sampling requirements for this test are aviation turbine fuel (a refined petroleum distillate) and kerosene
(another refined petroleum distillate), boiling between 140 and 300C, generally used in lighting and
The sample is burned in an enclosed wick-fed lamp that is calibrated daily against pure hydrocarbon
blends of known smoke point.
The maximum height of flame that can be achieved with the test fuel without smoking is determined to
the nearest 0.5 mm.
Calculation and reporting procedures.
In the use of a correspondence between smoke point and luminometer number, the relationship is based on
regression of data on 315 fuels having luminometer numbers falling within the range from -2 to 100. There
were 160 Jet A, A-1, JP-4, and JP-5 fuels in this group. The remaining fuels were diesel fuels, kerosenes,
blends of refinery fractions, and other miscellaneous petroleum fractions. The correlation coefficient is 0.95.
Reporting can be demonstrated through the confidence intervals about the correlation line which is
explainable almost completely by the inherent error in the smoke point and luminometer measurements.
This means that if there is a fuel-type effect different for each of the two methods, it is small and masked by
smoke point and luminometer number measurement errors.
PART F - D-3338 STANDARD TEST METHOD FOR ESTIMATION OF NET
HEAT OF COMBUSTION OF AVIATION FUELS
Requirements and Warnings.
Safety precautions are not necessary for this test because it is an empirical (by observation) method.
However, this method does not purport to address all of the safety concerns, if any, associated with its
Environmental precautions, if any, are the responsibility of the user of this method to establish
appropriate safety and heath practices and determine the applicability of regulatory limitations prior to
Apparatus for this test method is not required because it consists of correlating observations.
Sampling for this test consists of correlating various equations and formulas and substituting values
relating to various fuels into the equations.
Summary of Test Method.
A correlation (6) in inch-pound units has been established between the net heat of combustion and gravity,
aromatic content, and average volatility of the fuel. This correlation is converted to SI units; the relationship
is given in the following equations:
Type Fuel: All aviation gasolines, aircraft turbine and jet engine fuels
Qp1 = 16.24(G) - 3.007(A) + 0.01714(GxV)
-0.2983(AxG) + 0.00053(AxGxV) + 17685 (1)
Or in SI units
Qp2 = [5528.73 - 92.6499A = 10.1601 T
+ 0.314169AT] / D + 0.0791707A (2)
-0.00944893T - 0.000292178AT + 35.9936
Qp1 = net heat of combustion, BTU/lb, sulfur-free basis
Qp2 = net heat of combustion, MJ/kg, sulfur-free basis