Manual of Petroleum Measurement Standards Chapter 9.1

Standard Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method

THIRD EDITION, DECEMBER 2012

Manual of Petroleum Measurement Standards Chapter 9.1

Standard Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method

Measurement Coordination

THIRD EDITION, DECEMBER 2012

Special Notes

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Copyright © 2012 American Petroleum Institute

Foreword

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Contents

Page

1. Scope 1

2. Referenced Documents 1

3. Terminology 2

4. Summary of Test Method 2

5. Significance and Use 2

6. Apparatus 3

7. Sampling 3

8. Apparatus Verification or Certification 4

9. Procedure 4

10. Calculation 5

11. Report 7

12. Precision and Bias 7

13. Keywords 7

Annex A.1 (Mandatory Information) Apparatus 7

Summary of Changes 8

Figures

1. Hydrometer Scale Reading for Transparent Liquids 5

2. Hydrometer Scale Reading for Opaque Fluids 5

Tables

1. Recommended Hydrometers 3

2. Recommended Thermometers 3

3. Precision Values 7

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Designation: D1298 − 12b

Manual of Petroleum Measurement Standards (MPMS), Chapter 9.1

Standard Test Method for

Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method1

This standard is issued under the fixed designation D1298; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.

1. Scope*

   1. This test method covers the laboratory determination using a glass hydrometer 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 pressure 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.

   2. The initial hydrometer readings obtained are uncor- rected hydrometer readings and not density measurements. Readings are measured on a hydrometer at either the reference temperature or at another convenient temperature, and readings are corrected for the meniscus effect, the thermal glass expan- sion effect, alternate calibration temperature effects and 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.

   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 Petroleum Measurement Tables (API MPMS Chapter 11.1), or both, or tables, as applicable.

   4. The initial hydrometer readings determined in the labo- ratory shall be recorded before performing any calculations. The calculations required in Section 10 shall be applied to the initial hydrometer reading with observations and results re- ported as required by Section 11 prior to use in a subsequent calculation procedure (ticket calculation, meter factor calculation, or base prover volume determination).

   5. Annex A1 contains a procedure for verifying or certify- ing the equipment for this test method.

   6. The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only.

   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 of regulatory limitations prior to use.

      
      

2. Referenced Documents

   1. ASTM Standards:2

      D1250 Guide for Use of the Petroleum Measurement Tables 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

      E1 Specification for ASTM Liquid-in-Glass Thermometers E100 Specification for ASTM Hydrometers

   2. API Standards:3

MPMS Chapter 8.1 Manual Sampling of Petroleum and Petroleum Products (ASTM Practice D4057)

MPMS Chapter 8.2 Automatic Sampling of Petroleum and Petroleum Products (ASTM Practice D4177)

MPMS Chapter 8.3 Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products (ASTM Practice D5854)

MPMS Chapter 11.1 Temperature and Pressure Volume Cor- rection Factors for Generalized Crude Oils, Refined Prod- ucts and Lubricating Oils (Adjunct to ASTM D1250)

1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and the API Committee on Petroleum Measurement, and is the direct responsibility of Subcommittee D02.02 /COMQ, the joint ASTM-API Committee on Hydrocarbon Measurement for Custody Transfer (Joint ASTM-API).

Current edition approved June 1, 2012. Published October 2012. Originally approved in 1953. Last previous edition approved in 2012 as D1298–12a. DOI: 10.1520/D1298-12B.

2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website.

3 Published as Manual of Petroleum Measurement Standards. Available from the American Petroleum Institute (API), 1220 L St., NW, Washington, DC 20005.

*A Summary of Changes section appears at the end of this standard

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