Manual of Petroleum Measurement Standards Chapter 9—Density Determination Section 3—Standard Test Method for Density@ Relative Density@ and API Gravity of Crude Petroleum and Liquid Petroleum Products by Thermohydrometer Method (Second Edition)
This test method covers the determination@ using a glass thermohydrometer@ of the density@ relative density (specific gravity)@ or API gravity of crude petroleum and liquid petroleum products with Reid vapor pressures of 101.325 kPa (14.696 psi) or less. Values are determined at existing temperatures and corrected to 15??or 60??by means of international standard tables. The values stated in either SI units or inch pound-units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore@ each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. This standard does not purport to address all of the safety concerns@ if any@ 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.