Manual of Petroleum Measurement Standards Chapter 9 - Density Determination Section 1 - Standard Test Method for Density@ Relative Density (Specific Gravity)@ or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method (Second Edi
This test method covers the laboratory determination using a glass hydrometer@ of the density@ relative density (specific gravity)@ or API gravity of crude petroleum@ petroleum products@ or mixtures of petroleum and nonpetroleum products normally handled as liquids@ and having a Reid vapor pressure of 101.325 kPa (14.696 psi) or less. Values are measured on a hydrometer at either the reference temperature or at another convenient temperature@ and readings corrected to the reference temperature by means of the Petroleum Measurement Tables; values obtained at other than the reference temperature being hydrometer readings and not density measurements. Values determined as density@ relative density@ or API gravity can be converted to equivalent values in the other units at alternate reference temperatures by means of the Petroleum Measurement Tables. Annex A1 contains a procedure for verifying or certifying the equipment for this test method. 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.