API MPMS 9.3-2012 pdf free download

API MPMS 9.3-2012 pdf free download.Manual of Petroleum Measurement Standards Chapter 9.3 Standard Test Method for Density, Relative Density, and API Gravity of Crude Petroleum and Liquid Petroleum Products by Thermohydrometer Method.
1. Scope* 1.1 This test method covers the determination, using a glass thermohydrometer in conjunction with a series of calculations, of the density, relative density, or API gravity of crude petroleum, petroleum products, or mixtures of petroleum and nonpetroleum products normally handled as liquids and having a Reid vapor pressures of 101.325 kPa (14.696 psi) or less. Values are determined at existing temperatures and corrected to 15°C or 60°F by means of a series of calculations and international standard tables. 1.2 The initial thermohydrometer readings obtained are uncorrected hydrometer readings and not density measure- ments. Readings are measured on a thermohydrometer at either the reference temperature or at another convenient temperature, and readings are corrected for the meniscus effect, the thermal glass expansion effect, alternate calibration tem- perature effects and to the reference temperature by means of calculations and Adjunct to D1250 Guide for Use of the Petroleum Measurement Tables (API MPMS Chapter 11.1). 1.3 Readings determined as density, relative density, or API gravity can be converted to equivalent values in the other units or alternate reference temperatures by means of Interconver- sion Procedures (API MPMS Chapter 11.5) or Adjunct to D1250 Guide for Use of the Petroleum Measurement Tables (API MPMS Chapter 11.1), or both, or tables as applicable. 1.4 The initial thermohydrometer reading shall be recorded before performing any calculations. The calculations required in Section 9 shall be applied to the initial thermohydrometer reading with observations and results reported as required by Section 11 prior to use in a subsequent calculation procedure (measurement ticket calculation, meter factor calculation, or base prover volume determination). 1.5 Annex A1 contains a procedure for verifying or certify- ing the equipment of this test method. 1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.7 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 appro- priate safety and health practices and determine the applica- bility ofregulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D1250 Guide for Use of the Petroleum Measurement Tables D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Prod- ucts by Hydrometer Method D4057 Practice for Manual Sampling of Petroleum and Petroleum Products D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants E100 Specification for ASTM Hydrometers
3.1.4 observed values, n—hydrometer readings observed at a temperature other than the defined reference temperature. 3.1.4.1 Discussion—These values are only hydrometer read- ings and not density, relative density, or API gravity at the temperature. 3.1.5 relative density, n—the ratio of the mass of a given volume of liquid at a specific temperature to the mass of an equal volume of pure water at the same or different tempera- ture. Both reference temperatures shall be explicitly stated. 3.1.5.1 Discussion—Common reference temperatures in- clude 15/15°C, 60/60°F, 20/20°C, and 20/4°C. The historic term specific gravity may still be found. 3.1.6 thermohydrometer, n—a glass hydrometer with a self- contained thermometer. 4. Summary of Test Method 4.1 The density or API gravity, after temperature equilib- rium has been reached, is read by observing the freely floating thermohydrometer and noting the graduation nearest to the apparent intersection of the horizontal plane surface of the liquid with the vertical scale of the hydrometer after tempera- ture equilibrium has been reached. The observed thermohy- drometer reading is reduced to the reference temperature value by means of the Petroleum Measurement Tables (the appropri- ate adjunct to Adjunct to D1250 Guide for Petroleum Mea- surement Tables (API MPMS Chapter 11.1) and observed temperature from the enclosed thermometer.