ASTM D4893 Standard Test Method for Determination of Pitch Volatility
4. Apparatus
4.1 Aluminum Block, 4 1/2-in. outside diameter, composed of two sections (Figs. 1-4).
4.1.1 The top block is maintained at a chosen constant temperature according to the signal from the thermocouple inserted into the thermowell #1 near the center of the block. A proportional temperature controller regulates the heat input. Two insulated handles are attached to this part for easy handling. An additional thermowell #2, located in the center of the block, accommodates another thermocouple used only for the determination of the rate of temperature rise of the pitch. When the screw at the bottom of the #2 well is taken out, the thermocouple can then be pushed down and inserted in pitch.
4.1.2 The bottom block has a cavity for the aluminum weighing dish. A spiral channel cut around the periphery of this part serves for preheating the nitrogen introduced at the measured rate (10 cm3/min) into the block for purging volatiles.
4.1.3 The test temperature, the same as that in the top block, is maintained by the second proportional temperature controller according to the signals of a thermocouple inserted in a thermowell #3 of the bottom block. There is a hole in the center of the bottom cylinder to accommodate the sample platform, a rod with a stainless steel disk welded to its top. The aluminum sample dish containing the sample rests on top of this disk during the test. The aluminum sample dish can be lifted out of the cavity by raising the disk up to the upper rim of the cavity.
4.2 Aluminum Weighing Dish.
4.3 Flowmeter, 0 to 25-cm3/min range.
4.4 Nitrogen Cylinder, equipped with a pressure regulator.
4.5 Timer, with an alarm.
4.6 Aluminum Plate, 5-by-5-in., approximately 20-gage.
