ASTM D891 Specific Gravity, Apparent, of Liquid Industrial Chemicals
Specific gravity, apparent, is the mass of a substance relative to the mass of water at a given temperature.(This is closely related to specific gravity (relative density) which is the ratio of density of the substance to the density of water at a given temperature.) The specific gravity may help identify a substance, and in some cases may indicate the purity of a liquid. This method determines the specific gravity, apparent, by either hydrometer (method A) or pycnometer (method B).
For method A, the sample is placed into the test cylinder and brought to the test temperature. The hydrometer is inserted; the system equilibrated at the test temperature and the hydrometer is read. The specific gravity, apparent, is reported as a unitless number. For method B, the pycnometer is cleaned, weighed, filled with water, brought to the test temperature and again weighed. The process is repeated with sample. The specific gravity, apparent, is reported as a unitless number.
Related tests offered by Petro-Lubricant Testing Laboratories:
Consider a hydrometer test for oils when three decimal place accuracy is sufficient, and there is plenty of sample available:
ASTM D1298 Density, Relative Density (Specific Gravity) or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
Consider a pycnometer test for solids, greases and viscous oils:
PLTL-90 Density of Greases and Highly Viscous Liquids by Pycnometer
Consider a digital density meter test for low and medium density oils when high accuracy is required:
ASTM D4052 Density, Relative Density and API Gravity of Liquids by Digital Density Meter
Instructions:
Method A (hydrometer)