6. Apparatus
6.1 Oxidation Pressure Vessel, Burst Disc Assembly, Glass Sample Container and Cover, Accessories and Pressure Gage, as described in the Annex to Test Method D525.
NOTE 4 - Pressure vessels conforming to Test Method D525/1980 are also suitable, but the specified burst-disc shall be attached. The burst disc assembly shall be mechanically designed to ensure that it cannot be incorrectly fitted.
NOTE 5 - Precaution: Provision shall be made to safely vent any expelled gases or flames away from the operator, other personnel, or flammable materials as a safety precaution if the burst-disc ruptures.
6.2 Thermometer, having a range as shown below and conforming to the requirements as prescribed in Specification E 1, or specifications for IP thermometers:
NOTE 6 - Other temperature sensing devices that cover the temperature range of interest, such as thermocouples or platinum resistance thermometers, that can provide equivalent or better accuracy and precision, may be used in place of the thermometers specified in 6.2.
6.3 Drying Oven, air oven maintained at 100 to 150°C.
6.4 Forceps, corrosion-resistant, steel.
6.5 Filtering Crucible, sintered-glass, fine porosity.
6.6 Oxidation Bath, as described in the Annex to Test Method D525. The liquid shall be water or a mixture of ethylene glycol and water, as required. The temperature can be controlled thermostatically at 100 +/- 0.2°C, or by maintaining it at its boiling point, which must be between 99.5 to 100.5°C. If a liquid medium other than water is used, an appropriate mechanical stirrer/mixer shall be used to maintain uniformity of the liquid bath at 100 +/- 0.2°C. A non self-resettable device shall be fitted on all new baths to ensure that the heater is switched off if the liquid bath falls below a safe level. Users of older baths without this device are strongly urged to have the equipment retrofitted to ensure safe operation.
NOTE 7 - Electric heating blocks are known to be used. These blocks can have heating capacities, heating rates, and heat transfer characteristics that differ from those of a liquid bath. An electric heating block may be used in place of the liquid bath as long as the sample heating rate and sample temperature are demonstrated to be equivalent to that of the liquid bath.
6.7 Cooling Vessel - A desiccator or other type of tightly covered vessel for cooling the beakers before weighing. The use of a drying agent is not recommended.
7. Reagents and Materials
7.1 Gum Solvent - A mixture of equal volumes of toluene and acetone.
7.2 Oxygen, commercially available extra dry oxygen of not less than 99.6 % purity.
8. Sampling
8.1 Sample in accordance with the procedure for oxidation stability, as described in Practice D4057.