ASTM D2386 standard test method for freezing point of aviation fuels
8. Report
8.1 The observed freezing point determined in Section 7 shall be corrected by applying the relevant thermometer correction resulting from the checks described in Note 3. Where the observed freezing point falls between two calibration temperatures, the correction at the observed temperature shall be obtained by linear interpolation. Report the corrected temperature of crystal disappearance to the nearest 0.5°C as the freezing point, Test Method D2386.
NOTE 7 - When results are desired in degrees Fahrenheit, test results obtained in degrees Celsius should be converted to the nearest whole degree Fahrenheit. Interim Celsius freezing points should carry the best precision available for subsequent conversion to degrees Fahrenheit.
9. Precision and Bias
9.1 Precision - The precision of this test method was obtained by the statistical examination of the results of 14 samples of fuel consisting of Jet A, Jet A1, Jet B, JP-4, and JP-5 tested by 16 laboratories.
9.1.1 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 0.8°C only in one case in twenty.
9.1.2 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 2.3°C only in one case in twenty.
9.2 Bias - Because there are no liquid hydrocarbon mixtures of "known" freezing point, which simulate aviation fuels, bias cannot be established.
10. Keywords
10.1 aviation gasoline; aviation turbine fuels; crystallization point; determination; freezing point; low temperature tests; manual method; petroleum products; physical tests
