1、Designation: D7042 161Standard Test Method forDynamic Viscosity and Density of Liquids by StabingerViscometer (and the Calculation of Kinematic Viscosity)1This standard is issued under the fixed designation D7042; the number immediately following the designation indicates the year oforiginal adoptio
2、n 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.1NOTEThe title of Table X3.2 was corrected editorially in July 2016.1. Scope*1.1 This t
3、est method covers and specifies a procedure for theconcurrent measurement of both the dynamic viscosity, , andthe density, , of liquid petroleum products and crude oils, bothtransparent and opaque. The kinematic viscosity, , can beobtained by dividing the dynamic viscosity, , by the density, obtaine
4、d at the same test temperature.1.2 The result obtained from this test method is dependentupon the behavior of the sample and is intended for applicationto liquids for which primarily the shear stress and shear rate areproportional (Newtonian flow behavior).1.3 The precision has only been determined
5、for thosematerials, viscosity ranges, density ranges, and temperatures asindicated in Section 15 on Precision and Bias. The test methodcan be applied to a wider range of materials, viscosity, density,and temperature. For materials not listed in Section 15 onPrecision and Bias, the precision and bias
6、 may not be appli-cable.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 st
7、andard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation
8、of Dynamic Viscos-ity)D975 Specification for Diesel Fuel OilsD2162 Practice for Basic Calibration of Master Viscometersand Viscosity Oil StandardsD2270 Practice for Calculating Viscosity Index from Kine-matic Viscosity at 40 C and 100 CD4052 Test Method for Density, Relative Density, and APIGravity
9、of Liquids by Digital Density MeterD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6617
10、 Practice for Laboratory Bias Detection Using SingleTest Result from Standard MaterialD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a MaterialD6751 Specification for Biodiesel Fuel Blend Stock (B100
11、)for Middle Distillate FuelsD7467 Specification for Diesel Fuel Oil, Biodiesel Blend(B6 to B20)2.2 ISO Standards:3ISO 5725 Accuracy (Trueness and Precision) of Measure-ment Methods and ResultsISO 8217 Specifications for Marine FuelsISO/IEC 17025 General Requirements for the Competenceof Testing and
12、Calibration Laboratories2.3 Other Documents:4NIST Technical Note 1297 Guideline for Evaluating andExpressing the Uncertainty of NIST Measurement Results1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibilit
13、y ofSubcommittee D02.07 on Flow Properties.Current edition approved May 15, 2016. Published June 2016. Originallyapproved in 2004. Last previous edition approved in 2014 as D7042 14.DOI:10.1520/D7042-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Ser
14、vice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from National Instit
15、ute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Term
16、inology3.1 Definitions:3.1.1 density (), nmass per unit volume.3.1.2 dynamic viscosity (), nthe ratio between the appliedshear stress and rate of shear of a liquid.3.1.2.1 DiscussionIt is sometimes called the coefficient ofdynamic viscosity or, simply, viscosity. Thus, dynamic viscos-ity is a measur
17、e of the resistance to flow or to deformation ofa liquid under external shear forces.3.1.2.2 DiscussionThe term dynamic viscosity can also beused in a different context to denote a frequency-dependentquantity in which shear stress and shear rate have a sinusoidaltime dependence.3.1.3 kinematic visco
18、sity (), nthe ratio of the dynamicviscosity () to the density () of a liquid.3.1.3.1 DiscussionFor gravity flow under a given hydro-static head, the pressure head of a liquid is proportional to itsdensity (). Therefore the kinematic viscosity () is a measureof the resistance to flow of a liquid unde
19、r gravity.3.1.4 relative density (also called specific gravity (SG),nthe ratio of the density of a material at a stated temperatureto the density of a reference material (usually water) at a statedtemperature.4. Summary of Test Method4.1 The test specimen is introduced into the measuring cells,which
20、 are at a closely controlled and known temperature. Themeasuring cells consist of a pair of rotating concentric cylin-ders and an oscillating U-tube. The dynamic viscosity isdetermined from the equilibrium rotational speed of the innercylinder under the influence of the shear stress of the testspeci
21、men and an eddy current brake in conjunction withadjustment data. The density is determined by the oscillationfrequency of the U-tube in conjunction with adjustment data.The kinematic viscosity is calculated by dividing the dynamicviscosity by the density.5. Significance and Use5.1 Many petroleum pr
22、oducts, and some non-petroleummaterials, are used as lubricants and the correct operation ofthe equipment depends upon the appropriate viscosity of theliquid being used. In addition, the viscosity of many petroleumfuels is important for the estimation of optimum storage,handling, and operational con
23、ditions. Thus, the accurate deter-mination of viscosity is essential to many product specifica-tions.5.2 Density is a fundamental physical property that can beused in conjunction with other properties to characterize boththe light and heavy fractions of petroleum and petroleumproducts.5.3 Determinat
24、ion 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 Stabinger Viscometer5,66.1.1 Viscosity MeasurementThe Stabinger viscometeruses a rotational coaxial cylinder measuring s
25、ystem. The outercylinder (tube) is driven by a motor at a constant and knownrotational speed. The low-density inner cylinder (rotor) is heldin the axis of rotation by the centrifugal forces of the higherdensity sample and in its longitudinal position by the magnetand the soft iron ring. Consequently
26、, the system works free ofbearing friction as found in rotational viscometers. A perma-nent magnet in the inner cylinder induces eddy currents in thesurrounding copper casing. The rotational speed of the innercylinder establishes itself as the result of the equilibriumbetween the driving torque of t
27、he viscous forces and theretarding eddy current torque. This rotational speed is mea-sured by an electronic system (Hall effect sensor) by countingthe frequency of the rotating magnetic field (see Fig. 1 and Fig.2, No. 2).6.1.2 Density MeasurementThe digital density analyzeruses a U-shaped oscillati
28、ng sample tube and a system forelectronic excitation and frequency counting (see Fig. 2, No.3).6.1.3 Temperature ControlThe copper block surroundsboth the viscosity and the density measuring cell in a way thatboth cells are held at the same temperature. A thermoelectricheating and cooling system (se
29、e Fig. 2, No. 1) ensures thetemperature stability of the copper block within 60.005 Cfrom the set temperature at the position of the viscosity cellover the whole temperature range. The uncertainty (k = 2; 95 %confidence level) of the temperature calibration shall be nomore than 60.03 C over the rang
30、e from 15 C to 100 C.Outside this range the calibration uncertainty shall be no morethan 60.05 C.5The Stabinger viscometer is covered by a patent. Interested parties are invitedto submit information regarding the identification of an alternative to this patenteditem to the ASTM International headqua
31、rters. Your comments will receive carefulconsideration at a meeting of the responsible technical committee, which you mayattend.6The sole source of supply of the apparatus known to the committee at this timeis Anton Paar GmbH, Anton-Paar-Str. 20, A-8054 Graz, Austria. If you are aware ofalternative
32、suppliers, please provide this information to ASTM Internationalheadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend.FIG. 1 Viscosity CellD7042 16126.1.4 The thermal equilibration time depends on the heatcapacity and
33、conductivity of the liquid and on the differencebetween injection temperature and test temperature. Adequatetemperature equilibration of the test specimen is automaticallydetermined when successive viscosity values are constantwithin 60.07 % over 1 min and successive density values areconstant withi
34、n 60.00003 g/cm3over 60 s.NOTE 1The Stabinger Viscometer, manufactured by Anton PaarGmbH, fulfills the stated requirements when operated in the most precisemode of operation.6.2 Syringes, commercially available, at least 5 mL involume, with a Luer tip.All construction materials for syringesshall be
35、fully compatible with all sample liquids and cleaningagents, which contact them.6.3 Flow-Through or Pressure Adapter, for use as an alter-native means of introducing the test specimen into the mea-suring cells either by pressure or by suction, provided thatsufficient care and control is used to avoi
36、d any bubbleformation in the test specimen. All construction materials foradaptors shall be fully compatible with all sample liquids andcleaning agents, which contact them.6.4 Hot Filling Adapter, for use with manual syringe fillingfor the purpose of preventing the precipitation of waxycomponents di
37、ssolved in sample and lowering sample viscosityfor easier sample introduction and cleaning routines.6.5 Autosampler, for use in automated injection analyses.The autosampler shall be designed to ensure the integrity of thetest specimen prior to and during the analysis and be equippedto transfer a rep
38、resentative portion of test specimen into themeasuring cells. The autosampler shall transfer the test speci-men from the sample vial to the measuring cells of theapparatus without interfering with the integrity of the testspecimen. The autosampler shall be able to mimic the proce-dure for sample han
39、dling as set forth in 11.1 and 11.2. Theautosampler may have heating capability as a means to preventthe precipitation of waxy components dissolved in the sampleand lower the viscosity of the sample for filling the measuringcells.6.6 Screen, with an aperture of 75 m, to remove particlesfrom the samp
40、le.6.7 Magnet, strong enough to remove iron fillings from thesample. Magnetic stirring rods are suitable.6.8 Ultrasonic Bath, Unheated (optional), with an operatingfrequency between 25 kHz to 60 kHz and a typical poweroutput of 100 W, of suitable dimensions to hold container(s)placed inside of bath,
41、 for use in effectively dissipating andremoving air or gas bubbles that can be entrained in viscoussample types prior to analysis. It is permissible to use ultra-sonic baths with operating frequencies and power outputsoutside this range, however it is the responsibility of thelaboratory to conduct a
42、 data comparison study to confirm thatresults determined with and without the use of such ultrasonicbaths does not materially impact results.7. Reagents and Materials7.1 Sample Solvent, completely miscible with the sample.7.1.1 For most samples, a volatile petroleum spirit ornaphtha is suitable. If
43、the solvent dries up without residues inan applicable time frame, the use of a separate drying solventis not required.7.1.2 For residual fuels, a prewash with an aromatic solventsuch as toluene or xylene may be necessary to remove asphalticmaterial.7.2 Drying Solvent, a volatile solvent miscible wit
44、h thesample solvent (see 7.1).7.2.1 Highly concentrated ethanol (96 % or higher) is suit-able.7.3 Dry Air or Nitrogen, for blowing the measuring cells.7.3.1 If the measuring cell temperature is below or near thedew point temperature of the ambient air, the use of anappropriate desiccator is required
45、.8. Sampling, Test Specimens, and Test Units8.1 General Considerations and Guidelines:8.1.1 Sampling is defined as all the steps required to obtainan aliquot of the contents of any pipe, tank, or other system,and to place the sample into the laboratory test container. Thelaboratory test container an
46、d sample volume shall be ofsufficient capacity to mix the sample and obtain a homoge-neous sample for analysis.8.1.2 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 6.8) without theheater t
47、urned on (if so equipped), has been found effective indissipating bubbles typically within 1 min.8.1.3 ParticlesFor samples that are likely to containparticles (for example, used oils or crude oils) pass the samplethrough a 75 m screen to remove the particles. For theremoval of iron filings the use
48、of a magnet is appropriate. Waxysamples must be heated to dissolve the wax crystals prior tofiltration and a preheated filter shall be used.8.1.4 Test SpecimenA portion or volume of sample ob-tained from the laboratory sample and delivered to the mea-suring cells. The test specimen is obtained as fo
49、llows:FIG. 2 Cell BlockD7042 16138.1.4.1 Mix the sample, if required, to homogenize. Mixingat room temperature in an open container can result in the lossof volatile material; mixing in closed, pressurized containers,or at sub-ambient temperatures is recommended.8.1.4.2 Draw the test specimen from a properly mixedlaboratory sample using an appropriate syringe. Alternatively,if the proper attachments and connecting tubes are used, thetest specimen may be delivered directly to the measuring cellsusing a flow through or pressure adapter (s
