5.1 This test method is intended for use as a guide in cases where experimental determination of heat of combustion is not available and cannot be made conveniently and where an estimate is considered satisfactory. It is not intended as a substitute for experimental measurements of heat of combustion. Table 1 shows a summary for the range of each variable used in developing the correlation. The mean value and an estimate of its distribution about the mean, namely the standard deviation, is shown. This indicates, for example, that the mean density for all fuels used in developing the correlation was 779.3 kg/m3 and that two thirds of the samples had a density between 721.4 and 837.1 kg/m3, that is, plus or minus one standard deviation. The correlation is most accurate when the values of the variables used are within one standard deviation of the mean, but is useful up to two standard deviations of the mean. The use of this correlation may be applicable to other hydrocarbon distillates and pure hydrocarbons; however, only limited data on non-aviation fuels over the entire range of the variables were included in the correlation.
TABLE 1 Mean and Standard Deviation of the Variables
| Variable | Mean | Standard |
| Aromatics, volume % | 13.5 | 23.9 |
| Density, kg/m3 8201;[°API] | 779.3 [50.0] | 58.0 [13.5] |
| Volatility, °C [°F] | 171.11 [340] | 57.2 [103] |
| Heat of combustion, MJ/kg [Btu/lb] |
|