ASTM D5985 Test Method for Pour Point of Petroleum Products (Rotational Method)
6. Apparatus
6.1 Automatic Apparatus - The automatic pour point apparatus described in the Annex A1 consists of a microprocessor controlled measuring unit that is capable of heating, cooling, rotating, and recording the temperature of the test specimen. The apparatus shall be equipped with a digital display, cooling/heating block assembly, turntable, test specimen cup and measuring head containing a counter-balanced pendulum and temperature measuring device.
6.2 Test Specimen Cup - The test specimen cup is a flat bottom aluminum cup with the dimensions in A1.2. To indicate the required fill level, the inside of the test cup is scribed at a height of 36 +/- 0.2 mm above the inside bottom. The outside bottom of the test cup has two indentions to facilitate the rotation of the test cup.
6.3 Circulating Bath - Refrigeration unit equipped with a circulating pump capable of maintaining a temperature at least 20°C colder than the lowest expected pour point to be measured.
7. Reagents and Material
7.1 Methyl Alcohol, anhydrous, for use as cooling medium in circulating bath.
7.2 Cleaning Solvents, suitable for cleaning and drying the specimen cup and pendulum, such as petroleum naptha and acetone.
NOTE 3 - Warning: Flammable. Liquid causes eye burns. Vapor harmful. May be fatal or cause blindness if swallowed or inhaled.
8. Sampling
8.1 Obtain a sample in accordance with Practices D4057 or by D4177.
8.2 Samples of very viscous materials can be warmed until they are reasonably fluid before they are transferred; however, no sample shall be heated more than is absolutely necessary. The sample shall not be heated and transferred into the test specimen cup unless its temperature is 70°C or lower.
NOTE 4 - In the event the sample has been heated above this temperature, allow the sample to cool until its temperature is at least 70°C before transferring.
9. Preparation of Apparatus
9.1 Prepare the instrument for operation in accordance with the manufacturer's instructions.
9.2 Clean and dry the test specimen cup and the cooling well using suitable solvents as prescribed by the apparatus manufacturer.
9.3 Prepare the refrigerated circulating bath for operation in accordance with the manufacturer's instructions and allow it to attain a temperature at least 20°C lower than the expected pour point of the sample.
10. Calibration and Standardization
10.1 Ensure that all of the manufacturer's instructions for calibrating, checking, and operating the apparatus are followed.
10.2 Adjust the position of the measuring pendulum, when necessary, according to the manufacturer's instructions.
10.3 A sample with a well documented pour point can be used to verify performance of the apparatus. Alternatively, a sample which has been extensively tested in a pour point interlaboratory study can be used.
