ASTM D5949 Test Method for Pour Point of Petroleum Products (Automatic Pressure Pulsing Method)
11. Procedure
11.1 Inspect the specimen cup to ensure that it is clean and dry. If needed, clean the cup in accordance with 11.3.
11.2 Deliver 0.150 mL +/- 0.005 mL of specimen into the specimen cup. Pipettes, syringes, or precision positive-displacement devices are suitable for use in delivering the specimen. Samples with an expected pour point above 36 °C or which appear solid at room temperature may be heated above 45 °C, but shall not be heated above 70 °C (see Note 4).
11.3 Clean the specimen out of the cup. The cup shall be cleaned to the point where no visible droplets of specimen remain in the cup. Non-abrasive absorbent materials, such as cotton swabs, are suitable for use in cleaning the specimen cup. Cleaning solvents able to clean the specimen and compatible with the components of the apparatus may also be used. Naphtha, hexane, and heptane are suitable as cleaning solvents.
11.4 Repeat steps 11.2 and 11.3.
11.5 Carefully measure 0.150 mL +/- 0.005 mL of the specimen into the specimen cup.
11.6 Close and lock the test chamber lid.
11.7 Follow the manufacturer's instructions for preheating the specimen.
11.8 Select the desired pour point testing interval: 1 °C or 3 °C.
11.9 Start the test program following the manufacturer's instructions. The specimen is first heated as specified in 11.7. It is then cooled by the Peltier device at a rate of 1.5 °C/min +/- 0.1 °C/min. The apparatus will apply a pulse of compressed gas onto the specimen surface every 1 °C or 3 °C drop in temperature depending on the testing interval specified in 11.8. The specimen is illuminated by the light source, and the movement of the specimen surface upon application of a pulse is monitored by an array of optical detectors. The test will continue until application of a pulse of compressed gas causes no observable movement on the specimen surface. This is the no-flow point of the specimen. The lowest temperature at which movement of the specimen surface is observed upon application of the pulse of compressed gas is recorded as the pour point. The pour point value shall be displayed as an integer temperature in multiples of 1 °C or 3 °C depending on the selected testing interval.
11.10 Open the test chamber lid to access the specimen cup and clean the specimen out of the specimen cup (see 11.3).
