1、Designation: D4052 09Standard Test Method forDensity, Relative Density, and API Gravity of Liquids byDigital Density Meter1This standard is issued under the fixed designation D4052; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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 standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method covers t
3、he determination of the density,relative density, and API Gravity of petroleum distillates andviscous oils that can be handled in a normal fashion as liquidsat the temperature of test, utilizing either manual or automatedsample injection equipment. Its application is restricted toliquids with total
4、vapor pressures (see Test Method D5191)typically below 100 kPa and viscosities (see Test Method D445or D7042) typically below about 15 000 mm2/s at the tempera-ture of test. The total vapor pressure limitation however can beextended to 100 kPa provided that it is first ascertained that nobubbles for
5、m in the U-shaped, oscillating tube, which canaffect the density determination. Some examples of productsthat may be tested by this procedure include: gasoline andgasoline-oxygenate blends, diesel, jet, basestocks, waxes, andlubricating oils.1.1.1 Waxes were not included in the 1999 interlaboratorys
6、tudy (ILS) sample set that was used to determine the currentprecision statements of the method, since all samples evaluatedat the time were analyzed at a test temperature of 15C. Waxsamples require a temperature cell operated at elevated tem-peratures necessary to ensure a liquid test specimen is in
7、tro-duced for analysis. Consult instrument manufacturer instruc-tions for appropriate guidance and precautions whenattempting to analyze wax sample types. Refer to the Precisionand Bias section of the method and Note 6 for more detailedinformation about the 1999 ILS that was conducted.1.2 In cases o
8、f dispute, the referee method is the one wheresamples are introduced manually as in 6.3 or 6.4, as appropri-ate for sample type.1.3 This test method should not be applied to samples sodark in color that the absence of air bubbles in the sample cellcannot be established with certainty. For the determ
9、ination ofdensity in crude oil samples use Test Method D5002.1.4 The values stated in SI units are regarded as thestandard, unless stated otherwise, such as the “torr” units ofpressure in Eq 1. The accepted units of measure for density aregrams per millilitre (g/mL) or kilograms per cubic metre(kg/m
10、3).1.5 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 limitations prior to use. For specifi
11、c hazardstatements, see 7.4, 7.5, and 10.3.2. Referenced Documents2.1 ASTM Standards:2D287 Test Method for API Gravity of Crude Petroleum andPetroleum Products (Hydrometer Method)D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D1193 Sp
12、ecification for Reagent WaterD1250 Guide for Use of the Petroleum Measurement TablesD1298 Test Method for Density, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD4057 Practice for Manual Sampling of Petroleum andPetroleum Produ
13、ctsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4377 Test Method for Water in Crude Oils by Potentio-metric Karl Fischer TitrationD5002 Test Method for Density and Relative Density ofCrude Oils by Digital Density AnalyzerD5191 Test Method for Vapor Pressure of Petroleum P
14、rod-ucts (Mini Method)D7042 Test Method for Dynamic Viscosity and Density ofLiquids by Stabinger Viscometer (and the Calculation ofKinematic Viscosity)1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of Subcommitte
15、eD02.04.0D on Physical and Chemical Methods.This test method was adopted as a joint ASTM-IP standard in 1984.Current edition approved July 1, 2009. Published November 2009. Originallyapproved in 1981. Last previous edition approved in 2002 as D405296(2002)1.DOI: 10.1520/D4052-09.2For referenced ASTM
16、 standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM
17、 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions:3.1.1 adjustmentthe operation of bringing the instrumentto a state of performance suitable for its use, by setting oradjusting the density meter constants.3.1.1.1 Discuss
18、ionOn certain newer, commercially avail-able digital density analyzer instruments, an adjustment may bemade rather than calibrating the instrument. The adjustmentprocedure uses air and redistilled, freshly boiled and cooledwater as standards to establish the linearity of measurementsover a range of
19、operating temperatures.3.1.2 calibrationset of operations that establishes therelationship between the reference density of standards and thecorresponding density reading of the instrument.3.1.3 densitymass per unit volume at a specified tempera-ture.3.1.4 relative densitythe ratio of the density of
20、 a materialat a stated temperature to the density of water at a statedtemperature.4. Summary of Test Method4.1 A small volume (approximately 1 to 2 mL) of liquidsample is introduced into an oscillating sample tube and thechange in oscillating frequency caused by the change in themass of the tube is
21、used in conjunction with calibration data todetermine the density, relative density, or API Gravity of thesample. Both manual and automated injection techniques aredescribed.5. Significance and Use5.1 Density is a fundamental physical property that can beused in conjunction with other properties to
22、characterize boththe light and heavy fractions of petroleum and petroleumproducts.5.2 Determination of the density or relative density ofpetroleum and its products is necessary for the conversion ofmeasured volumes to volumes at the standard temperature of15C.6. Apparatus6.1 Digital Density Analyzer
23、A digital analyzer consistingof a U-shaped, oscillating sample tube and a system forelectronic excitation, frequency counting, and display. Theanalyzer shall accommodate the accurate measurement of thesample temperature during measurement or shall control thesample temperature as described in 6.2. T
24、he instrument shall becapable of meeting the precision requirements described in thistest method.6.2 Circulating Constant-Temperature Bath, (optional), ca-pable of maintaining the temperature of the circulating liquidconstant to 60.05C in the desired range. Temperature controlcan be maintained as pa
25、rt of the density analyzer instrumentpackage.6.3 Syringes, for use primarily in manual injections, at least2 mL in volume with a tip or an adapter tip that will fit theopening of the oscillating tube.6.4 Flow-Through or Pressure Adapter, for use as analternative means of introducing the sample into
26、the densityanalyzer either by a pump, by pressure, or by vacuum.NOTE 1It is highly recommended that a vacuum not be applied tosamples prone to light-end loss, as it can easily lead to the formation ofbubbles. It is recommended to fabricate a special cap or stopper for samplecontainers so that air, s
27、uch as from a squeeze pump, is used to displace atest specimen to the U-tube measuring cell by the flow-through method.6.5 Autosampler, required for use in automated injectionanalyses. The autosampler shall be designed to ensure theintegrity of the test specimen prior to and during the analysisand b
28、e equipped to transfer a representative portion of testspecimen to the digital density analyzer.6.6 Temperature Sensing Device (TSD), capable of monitor-ing the observed test temperature to within an accuracy of6 0.05C. If a liquid-in-glass thermometer is used as the TSD,it shall be calibrated and g
29、raduated to 0.1C, and have a holderthat can be attached to the instrument for setting and observingthe test temperature. In calibrating the thermometer, the icepoint and bore connections should be estimated to the nearest0.05C. For non-mercurial thermometers, the TSD device shallbe calibrated at lea
30、st annually against a certified and traceablestandard.6.7 Ultrasonic Bath, Unheated, (optional), of suitable di-mensions to hold container(s) placed inside of bath, for use ineffectively dissipating and removing air or gas bubbles thatmay be entrained in viscous sample types prior to analysis.7. Rea
31、gents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are availabl
32、e.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Ty
33、pe II of Specification D1193.7.3 Water, redistilled, freshly boiled and cooled reagentwater for use as a primary calibration standard.7.4 Cleaning Solvent, such as petroleum naphtha4(WarningPetroleum naphtha is extremely flammable), orother materials that are capable of flushing and removingsamples
34、entirely from the sample tube.7.5 Acetone, for flushing and drying the sample tube.(WarningExtremely flammable.)7.6 Dry Air, for drying the oscillator tube.8. Sampling, Test Specimens, and Test Units8.1 Sampling is defined as all the steps required to obtain analiquot of the contents of any pipe, ta
35、nk, or other system, andto place the sample into the laboratory test container. The3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for L
36、aboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.4Suitable solvent naphthas are marketed under various designations such as“Petroleum Ether,” “Ligroine,” or “Precipitation Naphtha.”D
37、4052 092laboratory test container and sample volume shall be ofsufficient capacity to mix the sample and obtain a homoge-neous sample for analysis.8.2 Laboratory SampleUse only representative samplesobtained as specified in Practices D4057 or D4177 for this testmethod.8.3 Test SpecimenAportion or vo
38、lume of sample obtainedfrom the laboratory sample and delivered to the densityanalyzer sample tube. The test specimen is obtained as follows:8.3.1 Mix the sample if required to homogenize taking careto avoid the introduction of air bubbles. The mixing may beaccomplished as described in Practice D417
39、7 or Test MethodD4377. Mixing at room temperature in an open container canresult in the loss of volatile material from certain sample types(e.g., gasoline samples), so mixing in closed, pressurizedcontainers or at sub-ambient temperatures is required for suchsample types where loss of volatile mater
40、ial is a potentialconcern. For some sample types, such as viscous lube oils thatare prone to having entrained air or gas bubbles present in thesample, the use of an ultrasonic bath (see 6.7) without theheater turned on (if so equipped), has been found effective indissipating bubbles typically within
41、 10 minutes.8.3.2 For manual injections, draw the test specimen from aproperly mixed laboratory sample using an appropriate sy-ringe. If the proper density analyzer attachments and connect-ing tubes are used, as described in 6.4, then the test specimencan be delivered directly to the analyzers sampl
42、e tube from themixing container. For automated injections, it is necessary tofirst transfer a portion of sample by appropriate means from aproperly mixed laboratory sample to the autosampler, and takethe necessary steps to ensure the integrity of the test specimenprior to and during the analysis. Fo
43、llow the manufacturersinstructions.9. Preparation of Apparatus9.1 Set up the density analyzer (including the constanttemperature bath and related attachments, if necessary) follow-ing the manufacturers instructions. Adjust the bath or internaltemperature control so that the desired test temperature
44、isestablished and maintained in the sample compartment of theanalyzer. Calibrate the instrument at the same temperature atwhich the density or relative density of the sample is to bemeasured or perform an adjustment (see 3.1.1.1 Discussion) inpreparation of analyzing samples. (WarningPrecise setting
45、and control of the test temperature in the sample tube isextremely important. An error of 0.1C can result in a changein density of one in the fourth decimal when measuring in unitsof g/mL.)10. Calibration of Apparatus10.1 As a minimum requirement, calibration of the instru-ment is required when firs
46、t set up, whenever the test tempera-ture is changed (unless the instrument is capable of performingan adjustment; see 3.1.1.1 Discussion), or as dictated by qualitycontrol (QC) sample results (see 11.1).10.2 When calibration of the instrument is required, it isnecessary to calculate the values of th
47、e constants A and B fromthe periods of oscillation (T) observed when the sample cellcontains air and redistilled, freshly boiled and cooled reagentwater. Other calibrating materials such as n-nonane,n-tridecane, cyclohexane, and n-hexadecane (for high tempera-ture applications) can also be used as a
48、ppropriate, provided thereference materials have density values that are certified andtraceable to national standards.NOTE 2On certain newer, commercially available instruments, aviscosity correction feature may be available and utilized in densitydeterminations to minimize potential biases. Refer t
49、o information in theSection 15 for more specifics.10.2.1 While monitoring the oscillator period, T, flush thesample tube with cleaning solvent, followed with an acetoneflush and dry with dry air. Contaminated or humid air can affectthe calibration. When these conditions exist in the laboratory,pass the air used for calibration through a suitable purificationand drying train. In addition, the inlet and outlet ports for theU-tube must be plugged during measurement of the calibrationair to prevent ingress of moist air.10.2.2 Allow the dry air in the U-tube to c
