1.1 This test method covers the determination of the specific gravity of drying oils, varnishes, alkyd resins, fatty acids, and related materials.

1.2 This test method is recommended where precision is required in the determination of specific gravity, such as establishing specifications or referee work.

1.2.1 For materials with a kinematic viscosity of 40 stokes or less, use the Leach type pycnometer.

1.2.2 For materials with a viscosity in excess of 40 stokes, use the Hubbard-type pycnometer.

1.2.3 For materials that are solid or semisolid at 25°C but liquid at slightly higher temperatures, use the Hubbard-type pycnometer.

Note 1-The weight per gallon cup method is satisfactory for most routine laboratory work although the precision does not equal that of the pycnometer method. The test method described herein for use with the Hubbard-type pycnometer is applicable to the weight per gallon cup method, or Test Method D1475 may be used. Note 2-Hydrometers also provide a rapid method for checking specific gravity and are generally satisfactory for routine control work. However, the precision of the hydrometer method is not adequate where accurate results are required. Test Method D1298 covers the use of the hydrometer in the determination of specific gravity. Most ASTM Hydrometers (See Specification E100) are calibrated to read specific gravity at 15.5/15.5°C (60/60°F). Information on sources of hydrometers calibrated at 25/25°C is available at ASTM Headquarters.

1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. >For specific hazard statements, see Section 6.