1、Designation: D7042 10Standard 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 adoption
2、 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.1. Scope1.1 This test method specifies a procedure for the concurrentmeasurement of both
3、 the dynamic viscosity, h, and the density,r, of liquid petroleum products and crude oils, both transparentand opaque. The kinematic viscosity, n, can be obtained bydividing the dynamic viscosity, h, by the density, r, obtained atthe same test temperature.1.2 The result obtained from this test metho
4、d 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 While the precision has only been determined for baseoils in the viscosity range from 2.05 to 456 mPas at 40C andf
5、rom 0.83 to 31.6 mPas at 100C and in the density range from0.82 to 0.92 g/mL at 15C (see 15.4), the test method can beapplied to a wider range of materials, viscosity, density, andtemperature. For materials not listed in Precision and Bias(Section 15), the precision and bias may not be applicable.1.
6、4 The values stated in SI units are to be regarded as thestandard. No other units of measurement are included in thisstandard. The accepted units of measure for density are gramsper millilitre (g/mL) or kilograms per cubic metre (kg/m3).1.5 This standard does not purport to address all of thesafety
7、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 to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Vis
8、cosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2162 Practice for Basic Calibration of Master Viscometersand Viscosity Oil StandardsD2270 Practice for Calculating Viscosity Index from Kine-matic Viscosity at 40 and 100CD4052 Test Method for Density, Relative Density,
9、and APIGravity 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 and
10、LubricantsD6617 Practice for Laboratory Bias Detection Using SingleTest Result from Standard MaterialD6708 Practice for StatisticalAssessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material2.2 ISO Standards:3ISO 5725 Accuracy (true
11、ness and precision) of measure-ment methods and resultsISO/IEC 17025 General Requirements for the Competenceof Testing and Calibration Laboratories2.3 Other Documents:4NIST Technical Note 1297 Guideline for Evaluating andExpressing the Uncertainty of NIST Measurement Results3. Terminology3.1 Definit
12、ions:3.1.1 dynamic viscosity (h), nthe ratio between the ap-plied shear stress and rate of shear of a liquid.3.1.1.1 DiscussionIt is sometimes called the coefficient ofdynamic viscosity or, simply, viscosity. Thus, dynamic viscos-ity is a measure of the resistance to flow or to deformation ofa liqui
13、d under external shear forces.3.1.1.2 DiscussionThe term dynamic viscosity can alsobe used in a different context to denote a frequency-dependentquantity in which shear stress and shear rate have a sinusoidaltime dependence.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleu
14、m Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 2004. Last previous edition approved in 2004 as D704204.DOI:10.1520/D7042-10.2For referenced ASTM standards, visit
15、 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.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York,
16、NY 10036, http:/www.ansi.org.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.2 kinem
17、atic viscosity (n), nthe ratio of the dynamicviscosity (h) to the density (r) of a liquid.3.1.2.1 DiscussionFor gravity flow under a given hydro-static head, the pressure head of a liquid is proportional to itsdensity (r). Therefore the kinematic viscosity (n) is a measureof the resistance to flow o
18、f a liquid under gravity.3.1.3 density (r), nmass per unit volume.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 te
19、st specimen is introduced into the measuring cells,which 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
20、under the influence of the shear stress of the testspecimen 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
21、the density.5. Significance and Use5.1 Many petroleum products, 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 est
22、imation of optimum storage,handling, and operational conditions. 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 fra
23、ctions of petroleum and petroleumproducts.5.3 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 Stabinger Viscometer5,66.1.1 Viscosity measurementThe Stabinger
24、viscometeruses a rotational coaxial cylinder measuring system. 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 po
25、sition by the magnetand the soft iron ring. Consequently, 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
26、result of the equilibriumbetween the driving torque of the 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 Measurem
27、entThe digital density analyzeruses a U-shaped oscillating 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 tem
28、perature. A thermoelectricheating and cooling system (see Fig. 2, No. 1) ensures thetemperature stability of the copper block within 60.005Cfrom the set temperature at the position of the viscosity cellover the whole temperature range. The uncertainty (k = 2; 95 %confidence level) of the temperature
29、 calibration shall be nomore than 60.03C over the range from 15 to 100C. Outsidethis range the calibration uncertainty shall be no more than60.05C.6.1.4 The thermal equilibration time depends on the heatcapacity and conductivity of the liquid and on the differencebetween injection temperature and te
30、st 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 within 60.00003 g/mL over 1 min.6.2 Syringes, commercially available, at least 5 mL invol
31、ume, with a Luer tip.All construction materials for syringesshall be fully compatible with all sample liquids and cleaningagents, which contact them.6.3 Flow-Through or Pressure Adapter, for use as analternative means of introducing the test specimen into themeasuring cells either by pressure or by
32、suction, provided thatsufficient care and control is used to avoid any bubbleformation in the test specimen. All construction materials for5The Stabinger viscometer is covered by a patent. Interested parties are invitedto submit information regarding the identification of an alternative to this pate
33、nteditem to the ASTM International headquarters. 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
34、, Austria. If you are aware ofalternative 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 102adaptors shall be fully com
35、patible with all sample liquids andcleaning agents, which contact them.6.4 Screen, with an aperture of 75 m, to remove particlesfrom the sample.6.5 Magnet, strong enough to remove iron fillings from thesample. Magnetic stirring rods are suitable.7. Reagents and Materials7.1 Sample Solvent, completel
36、y miscible with the sample.7.1.1 For most samples, a volatile petroleum spirit ornaphtha is suitable. If 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 o
37、r xylene may be necessary to remove asphalticmaterial.7.2 Drying Solvent, a volatile solvent miscible with 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 b
38、elow or near thedew point temperature of the ambient air, the use of anappropriate desiccator is required.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, tank, or other system, andto place the sample into t
39、he laboratory test container. Thelaboratory test container and sample volume shall be ofsufficient capacity to mix the sample and obtain a homoge-neous sample for analysis.8.2 ParticlesFor samples that are likely to contain par-ticles (for example, used oils or crude oils) pass the samplethrough a 7
40、5-m screen to remove the particles. For theremoval of iron filings the use of a magnet is appropriate. Waxysamples must be heated to dissolve the wax crystals prior tofiltration and a preheated filter shall be used.8.3 Test SpecimenAportion or volume of sample obtainedfrom the laboratory sample and
41、delivered to the measuringcells. The test specimen is obtained as follows:8.3.1 Mix the sample, if required, to homogenize. Mixing atroom temperature in an open container can result in the loss ofvolatile material; mixing in closed, pressurized containers, or atsub-ambient temperatures is recommende
42、d.8.3.2 Draw the test specimen from a properly mixed labo-ratory sample using an appropriate syringe.Alternatively, if theproper attachments and connecting tubes are used, the testspecimen can be delivered directly to the measuring cells fromthe mixing container. For waxy or other samples with a hig
43、hpour point, before drawing the test specimen, heat the labora-tory sample to the desired test temperature, which has to behigh enough to dissolve the wax crystals.9. Calibration and Verification9.1 Use only a calibrated apparatus as described in 6.1. Thecalibration shall be checked periodically usi
44、ng certified refer-ence standards as described in 9.2 and 9.3. The recommendedinterval for viscosity and density calibration is once a month,for temperature control once a year. For the calibrationprocedure follow the instructions of the manufacturer of theapparatus.9.2 Certified Viscosity and Densi
45、ty Reference StandardsThese are for use as confirmatory checks on the procedure inthe laboratory. Certified viscosity and density reference stan-dards shall be certified by a laboratory, which has shown tomeet the requirements of ISO/IEC 17025 or a correspondingnational standard by independent asses
46、sment. Viscosity stan-dards shall be traceable to master viscometer proceduresdescribed in Test Method D2162. Density standards shall havea certified uncertainty of the density values of 0.0001 g/mL.The uncertainty of the reference standards shall be stated foreach certified value (k = 2; 95 % confi
47、dence level). SeeISO 5725 or NIST Technical Note 1297.9.3 ThermometerFor calibration and adjustment of thetemperature control, a digital thermometer with a probe diam-eter of 6.25 mm and a maximal length of 80 mm shall be used.For smaller probes the use of an adapter is suitable. Theuncertainty (k =
48、 2; 95 % confidence level) of this thermometermust be no more than 60.01C and has to be certified by alaboratory which has shown to meet the requirements ofISO/IEC 17025 or a corresponding national standard byindependent assessment. A suitable thermometer is availablefrom the manufacturer of the app
49、aratus.9.4 Acceptable ToleranceIf the determined values of acalibration check measurement do not agree within the accept-able tolerance band of the certified values, as calculated fromAnnex A1, re-check each step in the procedure, including thespecial cleaning procedure from 12.2, to locate the source oferror.NOTE 1Values exceeding the acceptable tolerance are generallyattributable to deposits in the measuring cells that are not removed by theroutine flushing procedure.10. Adjustment10.1 An adjustment has to be carried out when repeatedcalibration che
