Standard Test Method for Density, Relative Density ...

1 Designation: D 1298 99 (Reapproved 2005)Designation: Manual of Petroleum Measurement Standards (MPMS), Chapter : 160/99An American National StandardStandard Test Method forDensity, Relative Density (Specific Gravity), or API Gravityof Crude Petroleum and Liquid Petroleum Products byHydrometer Method1 This Standard is issued under the fixed designation D 1298; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon ( ) indicates an editorial change since the last revision or Standard has been approved for use by agencies of the Department of This test Method covers the laboratory determinationusing a glass hydrometer, of the Density , Relative Density (specific gravity), or API gravity of crude petroleum, petroleumproducts, or mixtures of petroleum and nonpetroleum productsnormally handled as liquids, and having a Reid vapor pressureof kPa ( psi)

2 Or Values are measured on a hydrometer at either thereference temperature or at another convenient temperature,and readings corrected to the reference temperature by meansof the Petroleum Measurement Tables; values obtained at otherthan the reference temperature being hydrometer readings andnot Density Values determined as Density , Relative Density , or APIgravity can be converted to equivalent values in the other unitsat alternate reference temperatures by means of the PetroleumMeasurement A1contains a procedure for verifying or certify-ing the equipment for this test Standard does not purport to address all of thesafety concerns, if any, associated with its use.

3 It is theresponsibility of the user of this Standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to Referenced Standards:2D 97 Test Method for Pour Point of Petroleum ProductsD 323 Test Method for Vapor Pressure of Petroleum Prod-ucts (Reid Method )D 1250 Guide for Use of the Petroleum MeasurementTablesD 2500 Test Method for Cloud Point of Petroleum OilsD 3117 Test Method for Wax Appearance Point of DistillateFuelsD 4057 Practice for Manual Sampling of Petroleum andPetroleum Products (APIMPMSC hapter )D 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products (APIMPMSC hapter )D 5854 Practice for Mixing and Handling of LiquidSamples of Petroleum and Petroleum Products (APIMPMSC hapter )

4 E1 Specification for astm Liquid-in-Glass ThermometersE 100 Specification for astm Standards:3 MPMSC hapter Sampling of Petroleum andPetroleum Products ( astm PracticeD 4057)MPMSC hapter Sampling of Petroleum andPetroleum Products ( astm PracticeD 4177)1 This test Method is under the jurisdiction of astm Committee D02 onPetroleum Products and Lubricants and the API Committee on Petroleum Measure-ment, and is the direct responsibility of /COMQ, the joint astm -APIC ommittee on Static Petroleum edition approved Nov. 1, 2005. Published December 2005. Originallyapproved in 1953. Last previous edition approved in 1999 as D 1298 99 referenced astm standards, visit the astm website, , orcontact astm Customer Service at ForAnnual Book of ASTMS tandardsvolume information, refer to the Standard s Document Summary page onthe astm as Manual of Petroleum Measurement Standards.

5 Available from theAmerican Petroleum Institute (API), 1220 L St., NW, Washington, DC astm International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United and Handling of Liquid Samplesof Petroleum and Petroleum Products ( astm PracticeD 5854) of Petroleum Standards:4IP 389 Determination of wax appearance temperature(WAT) of middle distillate fuels by differential thermalanalysis (DTA) or differential scanning calorimetry (DSC)IP Standard Methods Book,Appendix A, Specifications IPStandard Standards:5 ISO 649-1 Laboratory glassware Density hydrometers forgeneral purpose Part 1: Specification3. of Terms Specific to This gravity,n a special function of Relative Density (specific gravity) 60/60 F, represented by: ~sp gr 60/60 F!

6 (1) No statement of reference temperatureis required, as 60 F is included in the point,n temperature at which a cloud of waxcrystals first appears in a liquid when it is cooled under ,n the mass of liquid per unit volume at 15 Cand kPa with the Standard unit of measurement beingkilograms per cubic Other reference temperatures, such as20 C, may be used for some products or in some preferred units of measurement (for example, kg/L org/mL) are still in values,n values observed at temperaturesother than the specified reference temperature. These values areonly hydrometer readings and not Density , Relative Density (specific gravity), or API gravity at that other point,n lowest temperature at which a testportion of crude petroleum or petroleum product will continueto flow when it is cooled under specified Density (specific gravity),n the ratio of themass of a given volume of liquid at a specific temperature tothe mass of an equal volume of pure water at the same ordifferent temperature.

7 Both reference temperatures shall beexplicitly Common reference temperatures in-clude 60/60 F, 20/20 C, 20/4 C. The historic deprecated termspecific gravity may still be appearance temperature (WAT),n temperatureat which waxy solids form when a crude petroleum orpetroleum product is cooled under specified Summary of Test The sample is brought to a specified temperature and atest portion is transferred to a hydrometer cylinder that hasbeen brought to approximately the same temperature. Theappropriate hydrometer, also at a similar temperature, islowered into the test portion and allowed to settle. Aftertemperature equilibrium has been reached, the hydrometerscale is read, and the temperature of the test portion is observed hydrometer reading is reduced to the referencetemperature by means of the Petroleum Measurement Tables.

8 Ifnecessary, the hydrometer cylinder and its contents are placedin a constant temperature bath to avoid excessive temperaturevariation during the Significance and Accurate determination of the Density , Relative Density (specific gravity), or API gravity of petroleum and its productsis necessary for the conversion of measured volumes tovolumes or masses, or both, at the Standard reference tempera-tures during custody This test Method is most suitable for determining thedensity, Relative Density (specific gravity), or API gravity oflow viscosity transparent liquids. This test Method can also beused for viscous liquids by allowing sufficient time for thehydrometer to reach equilibrium, and for opaque liquids byemploying a suitable meniscus When used in connection with bulk oil measurements,volume correction errors are minimized by observing thehydrometer reading at a temperature close to that of the bulk Density , Relative Density (specific gravity), or API grav-ity is a factor governing the quality and pricing of crudepetroleum.

9 However, this property of petroleum is an uncertainindication of its quality unless correlated with other Density is an important quality indicator for automotive,aviation and marine fuels, where it affects storage, handlingand , of glass, graduated in units of Density , Relative Density , or API gravity as required, conforming toSpecificationE 100orISO 649-1, and the requirements giveninTable The user should ascertain that the instruments used forthis test conform to the requirements set out above with respectto materials, dimensions, and scale errors. In cases where theinstrument is provided with a calibration certificate issued by arecognized standardizing body, the instrument is classed ascertified and the appropriate corrections listed shall be applied4 Available from Energy Institute, 61 New Cavendish St.

10 , London, W1M 8AR, from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 1 Recommended HydrometersUnitsRangeScaleAMeniscusTotal EachUnitIntervalAErrorACorrectionDensity , kg/m3at 15 C600 - 1100600 - 1100600 - + + + Density (specificgravity) 60/60 - - - + + + Density (specificgravity), 60/60 - 1 - + and Error relate to 1298 99 (2005)2to the observed readings. Instruments that satisfy the require-ments of this test Method , but are not provided with arecognized calibration certificate, are classed as , having range, graduation intervals andmaximum permitted scale error shown inTable 2and conform-ing to SpecificationE1or IP Appendix Alternate measuring devices or systems may be used,provided that the total uncertainty of the calibrated system is nogreater than when using liquid-in-glass Cylinder, clear glass, plastic ( ), ormetal.