ASTM D4893 Standard Test Method for Determination of Pitch Volatility
8. Procedure
8.1 Weigh 15 g of prepared sample into a tared aluminum weighing dish with precision of 0.1 mg.
8.2 Start nitrogen purge system at a rate 10 cm3/min +/- 0.1 cm3/min (10 mL/min +/- 0.1 mL/min).
8.3 Place top block onto bottom block, align the nitrogen inlet with nitrogen outlet, and heat to test temperature of 350°C (662°F).
8.4 Remove top block. Raise the sample platform up slightly above the rim of heating cavity and support with the aluminum plate inserted between the sample platform and top rim of the bottom block. Place the aluminum sample dish containing the sample onto the sample platform. Remove the inserted aluminum plate from below the sample platform and lower the sample carefully into the heated cavity. Close the bottom block with the top block and realign the nitrogen inlet with nitrogen outlet. This operation should be performed as quickly as possible to avoid excessive heat loss from the heated cavity.
8.5 Heat for 30 min +/- 10 s. Remove top block, raise sample platform, insert aluminum plate under the sample platform, sweep the sample off the sample platform on to the plate, and set aside.
8.6 Close the bottom block with the top block, realign the nitrogen inlet and outlet and allow the temperature in the blocks to stabilize before inserting subsequent sample.
8.7 When sample has cooled, approximately 2 min after removal or when crust has formed on top of sample, set aluminum dish containing sample into desiccator for 30 min. Determine weight loss.
8.8 Report in percent, mass loss for test temperature, 350°C.
V = (b x 100)/a
where:
V = volatility, %, mass loss,
b = mass loss, g, and
a = net mass of sample, g.
8.9 The exit opening of nitrogen purge, the sample platform, and the seat between the blocks must be kept free of deposits. For cleaning use acetone and a drill bit for opening the nitrogen exit.
