1、Designation: D1298 12b (Reapproved 2017)Manual of Petroleum Measurement Standards (MPMS), Chapter 9.1Standard Test Method forDensity, Relative Density, or API Gravity of Crude Petroleumand Liquid Petroleum Products by Hydrometer Method1This standard is issued under the fixed designation D1298; the n
2、umber 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 reapproval.This s
3、tandard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method covers the laboratory determinationusing a glass hydrometer in conjunction with a series ofcalculations, of the density, relative density, or API gravity ofcrude petroleum, petroleum products
4、, or mixtures of petroleumand nonpetroleum products normally handled as liquids, andhaving a Reid vapor pressure of 101.325 kPa (14.696 psi) orless. Values are determined at existing temperatures andcorrected to 15 C or 60 F by means of a series of calculationsand international standard tables.1.2 T
5、he initial hydrometer readings obtained are uncor-rected hydrometer readings and not density measurements.Readings are measured on a hydrometer at either the referencetemperature or at another convenient temperature, and readingsare corrected for the meniscus effect, the thermal glass expan-sion eff
6、ect, alternative calibration temperature effects and to thereference temperature by means of the Petroleum MeasurementTables; values obtained at other than the reference temperaturebeing hydrometer readings and not density measurements.1.3 Readings determined as density, relative density, or APIgrav
7、ity can be converted to equivalent values in the other unitsor alternative reference temperatures by means of Interconver-sion Procedures (API MPMS Chapter 11.5), or Adjunct toD1250 Guide for Petroleum Measurement Tables (API MPMSChapter 11.1), or both, or tables, as applicable.1.4 The initial hydro
8、meter readings determined in the labo-ratory shall be recorded before performing any calculations.The calculations required in Section 10 shall be applied to theinitial hydrometer reading with observations and results re-ported as required by Section 11 prior to use in a subsequentcalculation proced
9、ure (ticket calculation, meter factorcalculation, or base prover volume determination).1.5 Annex A1 contains a procedure for verifying or certify-ing the equipment for this test method.1.6 The values stated in SI units are to be regarded asstandard.1.6.1 ExceptionThe values given in parentheses are
10、pro-vided for information only.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitatio
11、ns prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Tech
12、nicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1250 Guide for Use of the Petroleum Measurement TablesD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5854 Practice for Mix
13、ing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsE1 Specification for ASTM Liquid-in-Glass ThermometersE100 Specification for ASTM Hydrometers1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and the API Committee
14、 onPetroleum Measurement, and is the direct responsibility of Subcommittee D02.02/COMQ, the joint ASTM-API Committee on Hydrocarbon Measurement forCustody Transfer (Joint ASTM-API). This test method has been approved by thesponsoring committees and accepted by the Cooperating Societies in accordance
15、with established procedures.Current edition approved July 15, 2017. Published July 2017. Originallyapproved in 1953. Last previous edition approved in 2012 as D1298 12b. DOI:10.1520/D1298-12BR17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
16、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website. Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220
17、 L Street NW, Washington DC 20005, USAThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Or
18、ganization Technical Barriers to Trade (TBT) Committee.12.2 API Standards:3MPMS Chapter 8.1 Manual Sampling of Petroleum andPetroleum Products (ASTM Practice D4057)MPMS Chapter 8.2 Automatic Sampling of Petroleum andPetroleum Products (ASTM Practice D4177)MPMS Chapter 8.3 Mixing and Handling of Liqu
19、id Samplesof Petroleum and Petroleum Products (ASTM PracticeD5854)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)MPMS Chapter 11.5 Density/Weight/Volume Intraconver-sion2.3 Energy Institu
20、te 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 Thermometers2.4 ISO Standards:5ISO 649-1 Laboratory glasswa
21、re Density hydrometers forgeneral purpose Part 1: Specification2.5 ASTM Adjuncts:Adjunct to D1250 Guide for Petroleum Measurement Tables(API MPMS Chapter 11.1)63. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 API gravity, na special function of relative density(specific gravity
22、) 60/60 F, represented by:API 5 141.5/relative density 60/60 F!# 2 131.5 (1)3.1.1.1 DiscussionNo statement of reference temperatureis required, as 60 F is included in the definition.3.1.2 cloud point, ntemperature at which a cloud of waxcrystals first appears in a liquid when it is cooled under spec
23、ificconditions.3.1.3 density, nthe mass of liquid per unit volume at 15 Cand 101.325 kPa with the standard unit of measurement beingkilograms per cubic metre.3.1.3.1 DiscussionOther reference temperatures, such as20 C, may be used for some products or in some locations.Less preferred units of measur
24、ement (for example, kg/L org/mL) are still in use.3.1.4 hydrometer reading, nthe point on the hydrometerscale at which the surface of the liquid cuts the scale.3.1.4.1 DiscussionIn practice for transparent fluids thiscan be readily determined by aligning the surface of the liquidon both sides of the
25、 hydrometer and reading the Hydrometerscale where these surface readings cut the scale (HydrometerReading Observed). For nontransparent fluids the point atwhich the liquid surface cuts the Hydrometer scale cannot bedetermined directly and requires a correction (Meniscus Cor-rection). The value repre
26、sented by the point (Meniscus Read-ing) at which the liquid sample rises above the main surface ofthe liquid subtracted from the value represented by where themain surface of the liquid cuts the Hydrometer scale is theamount of the correction or Meniscus correction. This menis-cus correction is docu
27、mented and then subtracted from thevalue represented by the Meniscus Reading to yield theHydrometer Reading corrected for the Meniscus (HydrometerReading Observed, Meniscus Corrected).3.1.5 observed values, nvalues observed at temperaturesother than the specified reference temperature. These values
28、areonly hydrometer readings and not density, relative density(specific gravity), or API gravity at that other temperature.3.1.6 pour point, nlowest temperature at which a testportion of crude petroleum or petroleum product will continueto flow when it is cooled under specified conditions.3.1.7 relat
29、ive density (specific gravity), nthe 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. Both reference temperatures shall beexplicitly stated.3.1.7.1 DiscussionCommon reference temperatures in-clude
30、60/60 F, 20 20 C, 20/4 C. The historic deprecatedterm specific gravity may still be found.3.1.8 wax appearance temperature (WAT), ntemperatureat which waxy solids form when a crude petroleum orpetroleum product is cooled under specified conditions.4. Summary of Test Method4.1 The sample is brought t
31、o a specified temperature and atest portion is transferred to a hydrometer cylinder that hasbeen brought to approximately the same temperature. Theappropriate hydrometer and thermometer, also at a similartemperature, are lowered into the test portion and allowed tosettle. After temperature equilibri
32、um has been reached, thehydrometer scale is read, and the temperature of the testportion is taken. The observed hydrometer reading is correctedfor the meniscus effect, the thermal glass expansion effect,alternative calibration temperature effects and then reduced tothe reference temperature by means
33、 of the volume correctionfactors or tables as applicable by use of the appropriateAdjunctto D1250 Guide for Petroleum Measurement Tables (APIMPMS Chapter 11.1) and observed temperature from thethermometer.4.2 If necessary, the hydrometer cylinder and its contentsare placed in a constant temperature
34、bath to avoid excessivetemperature variation during the test.5. Significance and Use5.1 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 stan
35、dard reference tempera-tures of 15 C or 60 F during custody transfer.3Published as Manual of Petroleum Measurement Standards. Available from theAmerican Petroleum Institute (API), 1220 L St., NW, Washington, DC 20005-4070,http:/www.api.org.4Available from Energy Institute, 61 New Cavendish St., Lond
36、on, W1G 7AR,U.K., http:/www.energyinst.org.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.6Available from ASTM International Headquarters. Order Adjunct No.ADJD1250. Original adjunct produced in 1983.D1298 12b (2017)25.2
37、 This procedure is most suitable for determining thedensity, relative density (specific gravity), or API gravity oflow viscosity transparent liquids. This procedure can also beused for viscous liquids by allowing sufficient time for thehydrometer to reach temperature equilibrium, and for opaqueliqui
38、ds by employing a suitable meniscus correction. Addition-ally for both transparent and opaque fluids the readings shall becorrected for the thermal glass expansion effect and alternativecalibration temperature effects before correcting to the refer-ence temperature.5.3 When used in connection with b
39、ulk oil measurements,volume correction errors are minimized by observing thehydrometer reading at a temperature close to that of the bulk oiltemperature.5.4 Density, relative density, or API gravity is a factorgoverning the quality and pricing of crude petroleum.However, this property of petroleum i
40、s an uncertain indicationof its quality unless correlated with other properties.5.5 Density is an important quality indicator for automotive,aviation and marine fuels, where it affects storage, handlingand combustion.6. Apparatus6.1 Hydrometers, of glass, graduated in units of density,relative densi
41、ty, or API gravity as required, conforming toSpecification E100 or ISO 649-1, and the requirements givenin Table 1.6.1.1 The user should ascertain that the instruments used forthis procedure conform to the requirements set out above withrespect to materials, dimensions, and scale errors. In caseswhe
42、re the instrument is provided with a calibration certificateissued by a recognized standardizing body, the instrument isclassed as certified and the appropriate corrections for themeniscus effect, the thermal glass expansion effect, and alter-native calibration temperature effects shall be applied t
43、o theobserved readings prior to corrections. Instruments that satisfythe requirements of this test method, but are not provided witha recognized calibration certificate, are classed as uncertified.6.2 Thermometers, having range, graduation intervals andmaximum permitted scale error shown in Table 2
44、and conform-ing to Specification E1 or IP Appendix A.6.2.1 Alternative measuring devices or systems may beused, provided that the total uncertainty of the calibratedsystem is no greater than that specified in 6.2. The statedrepeatability and reproducibility values are not applicable ifalternative fl
45、uids are used in the liquid-in-glass thermometers.6.3 Hydrometer Cylinder, clear glass, or plastic (see 6.3.1).The inside diameter of the cylinder shall be at least 25 mmgreater than the outside diameter of the hydrometer and theheight shall be such that the appropriate hydrometer floats inthe sampl
46、e test portion with at least 25 mm clearance betweenthe bottom of the hydrometer and the bottom of the cylinder.6.3.1 Hydrometer cylinders constructed of plastic materialsshall be resistant to discoloration or attack by oil samples andshall not affect the material being tested. They shall not become
47、opaque under prolonged exposure to sunlight.6.4 Constant-Temperature Bath, if required, of dimensionssuch that it can accommodate the hydrometer cylinder with thetest portion fully immersed below the test portion liquidsurface, and a temperature control system capable of maintain-ing the bath temper
48、ature within 0.25 C of the test temperaturethroughout the duration of the test.6.5 Stirring Rod, optional, of glass or plastic, approximately400 mm in length.7. Sampling7.1 Unless otherwise specified, samples of non-volatilepetroleum and petroleum products shall be taken by theprocedures described i
49、n Practice D4057 (API MPMS Chapter8.1) and D4177 (API MPMS Chapter 8.2).7.2 Samples of volatile crude petroleum or petroleum prod-ucts are preferably taken by Practice D4177 (API MPMSChapter 8.2), using a variable volume (floating piston) samplereceiver to minimize any loss of light components which mayaffect the accuracy of the density measurement. In the absenceof this facility, extreme care shall be taken to minimize theselosses, including the transfer of the sample to a chilledcontainer immediately after sampling.7.3 Sample MixingMay be
