ASTM D5304 Standard Test Method for Assessing Middle Distillate Fuel Storage Stability by Oxygen Overpressure
8. Sampling
8.1 Field Sampling - Field sampling should be in accordance with Practices D4057 or D4177. Bulk fuel to be sampled must be above its cloud point and thoroughly mixed prior to aliquot sampling. For field sampling and shipping, use only epoxy-lined steel cans that have been cleaned according to Practice D4306.
8.2 Laboratory Subsampling - Fuel to be sampled must be above its cloud point and thoroughly mixed prior to aliquot sampling. Use clean amber or clean borosilicate glass containers for laboratory handling. Fuel in clear bottles must be protected from light, for example, by wrapping in aluminum foil.
9. Preparation of Apparatus
9.1 Rinse the sample containers thoroughly with the TAM solvent followed by water. Then wash with a mildly alkaline or neutral pH laboratory detergent. Rinse with deionized or distilled water. Let bottles stand overnight with distilled water in them. Dry in a drying oven at 105 °C to 115 °C. Ensure the sample bottles are cleaned thoroughly. Leave no soap residue on the inside of the bottles (Note 1).
NOTE 1 - Even a slight soap residue left on the walls of the bottle could alter sediment results.
9.2 Soak the aluminum weighing dishes in fresh, clean TAM solvent for several minutes followed by drying in a drying oven at 105 °C to 115 °C. Even new aluminum dishes must be cleaned with TAM solvent and dried before the initial weighing. Two hours after removal from the oven, firmly nest one dish inside of another for each sample replicate and for each blank replicate to be run. This is both the adherent insolubles evaporation assembly and, in combination with two unweighed nylon membrane filters, the weighing assembly for each test sample or blank.
9.3 Using forceps, place two dry filters in the aluminum weighing dish assembly from 9.2 and weigh the entire assembly of two filters and two aluminum dishes to the nearest 0.1 mg. A separate two filter plus two weighing dish assembly (the so-called weighing assembly) is required for each sample and blank replicate. Weigh the filter and weighing dish assembly three times about one-half hour apart and take the average reading. This allows for changes in weight due to temperature and humidity.
9.4 Place the pressure vessel(s) specified in 6.2 in a heater specified in 6.3 to preheat to test temperature.
