5. Significance and Use
5.1 The pour point of a petroleum specimen is an index of the lowest temperature of its utility for certain applications.
6. Apparatus
6.1 Test Jar, cylindrical, of clear glass, flat bottom, 33.2 to 34.8-mm outside diameter, and 115 to 125 mm in height. The inside diameter of the jar can range from 30.0 to 32.4 mm, within the constraint that the wall thickness be no greater than 1.6 mm. The jar shall have a line to indicate a sample height 54 more or less 3 mm above the inside bottom. See Fig. 1.
6.2 Thermometers, having the following ranges and conforming to the requirements prescribed in Specification E 1 for thermometers:
6.2.1 Since separation of liquid column thermometers occasionally occurs and may escape detection, thermometers should be checked immediately prior to the test and used only if they prove accurate within more or less 1°C (for example ice point).
6.3 Cork, to fit the test jar, bored centrally for the test thermometer.
6.4 Jacket, watertight, cylindrical, metal, flat-bottomed, 115 more or less 3-mm depth, with inside diameter of 44.2 to 45.8 mm. It shall be supported in a vertical position in the cooling bath (see 6.7) so that not more than 25 mm projects out of the cooling medium, and shall be capable of being cleaned.
6.5 Disk, cork or felt, 6 mm thick to fit loosely inside the jacket.
6.6 Gasket, to fit snugly around the outside of the test jar and loosely inside the jacket. The gasket may be made of rubber, leather, or other material that is elastic enough to cling to the test jar and hard enough to hold its shape. Its purpose is to prevent the test jar from touching the jacket.
6.7 Bath or Baths, maintained at prescribed temperatures with a firm support to hold the jacket vertical. The required bath temperatures may be obtained by refrigeration if available, otherwise by suitable freezing mixtures. Freezing mixtures commonly used for temperatures down to those shown are as follows:
7. Reagents and Materials
7.1 The following solvents of technical grade are appropriate for low-temperature bath media.
7.1.1 Acetone, (Warning - Extremely flammable).
7.1.2 Alcohol, Ethanol (Warning - Flammable).
7.1.3 Alcohol, Methanol (Warning - Flammable. Vapor harmful).
7.1.4 Petroleum Naphtha, (Warning - Combustible. Vapor harmful).
7.1.5 Solid Carbon Dioxide, (Warning - Extremely cold -78.5°C).