1、Designation: D1298 12bDesignation: 160/99API Designation: 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 design
2、ation D1298; 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
3、 reapproval.1. Scope*1.1 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, or mixtures of petroleumand nonpetroleum products normally handle
4、d as liquids, andhaving a Reid vapor pressure of 101.325 kPa (14.696 psi) orless. Values are determined at existing temperatures andcorrected to 15C or 60F by means of a series of calculationsand international standard tables.1.2 The initial hydrometer readings obtained are uncor-rected hydrometer r
5、eadings 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 effect, alternate calibration temperature effects and to thereference te
6、mperature 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 APIgravity can be converted to equivalent values in the other unitsor alternat
7、e 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 hydrometer readings determined in the labo-ratory shall be recorded before per
8、forming 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 procedure (ticket calculation, meter factor calcula-tion, or base prover volume
9、 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. The values given in parentheses are provided forinformation only.1.7 This standard does not purport to address all of the
10、safety 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 limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1250 Guide for Use of the P
11、etroleum Measurement TablesD4057 Practice for Manual Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.1)D4177 Practice for Automatic Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.2)D5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum Pro
12、ducts (API MPMS Chapter8.3)E1 Specification for ASTM Liquid-in-Glass ThermometersE100 Specification for ASTM Hydrometers2.2 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 (
13、ASTM Practice D4177)MPMS Chapter 8.3 Mixing and Handling of Liquid Samplesof Petroleum and Petroleum Products (ASTM PracticeD5854)MPMS Chapter 11.1 Temperature and Pressure VolumeCorrection Factors for Generalized Crude Oils, RefinedProducts and Lubricating Oils (Adjunct to ASTM D1250)1This test met
14、hod 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 Subcommittee D02.02 /COMQ, the jointASTM-API Committee on Hydrocarbon Measurement for Custody Transfer (JointASTM-API).Current
15、edition approved June 1, 2012. Published October 2012. Originallyapproved in 1953. Last previous edition approved in 2012 as D129812a. DOI:10.1520/D1298-12B.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
16、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Published as Manual of Petroleum Measurement Standards. Available from theAmerican Petroleum Institute (API), 1220 L St., NW, Washington, DC 20005.1*A Summary of Changes section appears at the end of thi
17、s standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.MPMS Chapter 11.5 Density/Weight/Volume Intraconver-sion2.3 Energy Institute Standards:4IP 389 Determination of wax appearance temperature(WAT) of middle distillate fuels by d
18、ifferential thermalanalysis (DTA) or differential scanning calorimetry (DSC)IPStandard Methods Book, AppendixA, Specifications IPStandard Thermometers2.4 ISO Standards:5ISO 649-1 Laboratory glassware Density hydrometers forgeneral purpose Part 1: Specification2.5 ASTM Adjuncts:Adjunct to D1250 Guide
19、 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) 60/60F, represented by:API 5 141.5 / relative density 60/60 F!# 2 131.5 (1)3.1.1.1 DiscussionNo state
20、ment of reference temperatureis required, as 60F 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 specificconditions.3.1.3 density, nthe mass of liquid per unit volume at 15Cand 101.325 kPa with the standa
21、rd unit of measurement beingkilograms per cubic metre.3.1.3.1 DiscussionOther reference temperatures, such as20C, may be used for some products or in some locations.Less preferred units of measurement (for example, kg/L org/mL) are still in use.3.1.4 hydrometer reading, nthe point on the hydrometers
22、cale 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 hydrometer and reading the Hydrometerscale where these surface readings cut the scale (HydrometerReading
23、 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 represented by the point (Meniscus Read-ing) at which the liquid sample rises above the main surface ofthe liq
24、uid 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 documented and then subtracted from thevalue represented by the Meniscus Reading to yield theHydrometer Readi
25、ng corrected for the Meniscus (HydrometerReading Observed, Meniscus Corrected).3.1.5 observed values, nvalues 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 o
26、ther 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 relative density (specific gravity), nthe ratio of themass of a given volume of liquid at a specific temperatu
27、re 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 60/60F, 20/20C, 20/4C. The historic deprecated termspecific gravity may still be found.3.1.8 wax appearan
28、ce 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 to a specified temperature and atest portion is transferred to a hydrometer cylinder that hasbeen brought to
29、approximately the same temperature. Theappropriate hydrometer and thermometer, also at a similartemperature, are lowered into the test portion and allowed tosettle. After temperature equilibrium has been reached, thehydrometer scale is read, and the temperature of the testportion is taken. The obser
30、ved hydrometer reading is correctedfor the meniscus effect, the thermal glass expansion effect,alternate calibration temperature effects and then reduced to thereference temperature by means of the volume correctionfactors or tables as applicable by use of the appropriateAdjunctto D1250 Guide for Pe
31、troleum 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 bath to avoid excessivetemperature variation during the test.5. Significance and Use5.1 Accurate determination
32、 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 of 15C or 60F during custody transfer.5.2 This procedure is most suitable for det
33、ermining 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 opaqueliquids by employing a suitable meniscus corr
34、ection. Addition-ally for both transparent and opaque fluids the readings shall becorrected for the thermal glass expansion effect and alternatecalibration temperature effects before correcting to the refer-ence temperature.5.3 When used in connection with bulk oil measurements,volume correction err
35、ors are minimized by observing thehydrometer reading at a temperature close to that of the bulk oiltemperature.4Available from Energy Institute, 61 New Cavendish St., London, W1M 8AR,UK.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.6Availa
36、ble from ASTM International Headquarters. Order Adjunct No.ADJD1250. Original adjunct produced in 1983.D1298 12b25.4 Density, relative density, or API gravity is a factorgoverning the quality and pricing of crude petroleum. How-ever, this property of petroleum is an uncertain indication of itsqualit
37、y 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 density, or API gravity as required, confor
38、ming 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 caseswhere the instrument is provided with a c
39、alibration 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 to theobserved readings prior to correc
40、tions. 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 and conform-ing to Specification E1 or
41、 IP Appendix A.6.2.1 Alternate measuring devices or systems may be used,provided that the total uncertainty of the calibrated system is nogreater than that specified in 6.2. The stated repeatability andreproducibility values are not applicable if alternate fluids areused in the liquid-in-glass therm
42、ometers.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 sample test portion with at least 25 mm clearan
43、ce 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 becomeopaque under prolonged exposure to sunligh
44、t.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 temperature within 0.25C of the test temperature
45、throughout 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 in Practice D4057 (API MPMS Chapter8.1) and
46、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 meas
47、urement. 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 necessary to obtain a testportion representative of the bulk sample to be tested, butprecautions
48、 shall be taken to maintain the integrity of thesample during this operation. Mixing of volatile crude petro-leum or petroleum products containing water or sediments, orboth, or the heating of waxy volatile crude petroleum orpetroleum products may result in the loss of light components.The following
49、 subsections (7.3.1 to 7.3.4) will give someguidance on sample integrity maintenance.7.3.1 Volatile Crude Petroleum and Petroleum ProductsHaving an RVP Greater than 50 kPaMix the sample in itsoriginal closed container in order to minimize the loss of lightcomponents.NOTE 1Mixing volatile samples in open containers will lead to loss oflight components and consequently affect the value of the densityobtained.7.3.2 Waxy Crude PetroleumIf the petroleum has anexpected pour point above 10C, or a cloud point or WATabove 15C, warm the sample to a t
