5.1 The freezing point of an aviation fuel is the lowest temperature at which the fuel remains free of solid hydrocarbon crystals. These crystals can restrict the flow of fuel through the fuel system of the aircraft. The temperature of the fuel in the aircraft tank normally decreases during flight depending on aircraft speed, altitude, and flight duration. The freezing point of the fuel must always be lower than the minimum operational fuel temperature.

5.2 Petroleum blending operations require precise measurement of the freezing point.

5.3 This test method produces results which have been found to be equivalent to Test Method D2386 and expresses results to the nearest 0.1 °C, with improved precision over Test Method D2386. This test method also eliminates most of the operator time and judgment required by Test Method D2386.

5.4 When specification requires Test Method D2386, do not substitute this test method or any other test method.

1.1 This test method covers the determination of the temperature below which solid hydrocarbon crystals form in aviation turbine fuels.

1.2 This test method is designed to cover the temperature range of −80 °C to 20 °C; however, 2003 Joint ASTM/IP Interlaboratory Cooperative Test Program mentioned in 12.4 has only demonstrated the test method with fuels having freezing points in the range of −42 °C to −60 °C.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 7.1, 7.3, and 7.5.