1、Designation:D704210 Designation: D7042 11Standard 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
2、 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.1. Scope1.1 This test method covers and specifies a procedure for th
3、e concurrent measurement of both the dynamic viscosity, h, and thedensity, r, of liquid petroleum products and crude oils, both transparent and opaque. The kinematic viscosity, n, can be obtainedby dividing the dynamic viscosity, h, by the density, r, obtained at the same test temperature.1.2 The re
4、sult obtained from this test method is dependent upon the behavior of the sample and is intended for application toliquids for which primarily the shear stress and shear rate are proportional (Newtonian flow behavior).1.3 While the precision has only been determined for base oils in the viscosity ra
5、nge from 2.05 to 456 mPas at 40C and from0.83 to 31.6 mPas at 100C and in the density range from 0.82 to 0.92 g/mLg/cm3at 15C (see 15.415.5), the test method canbe applied to a wider range of materials, viscosity, density, and temperature. For materials not listed in Precision and Bias (Section15),
6、the precision and bias may not be applicable.1.4The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.The accepted units of measure for density are grams per millilitre (g/mL) or kilograms per cubic metre (kg/m3).1.4 The values
7、stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate
8、safety and health practices and to determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)D2162 Practice for Basic Calibration of Mas
9、ter Viscometers and Viscosity Oil StandardsD2270 Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100CD4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD6299 Practice for Applying Statistical Quality Assurance and Control C
10、harting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsD6617 Practice for Laboratory Bias Detection Using Single Test Result from Standard MaterialD6708 Practice f
11、or Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a Material2.2 ISO Standards:3ISO 5725 Accuracy (trueness and precision) of measurement methods and resultsISO/IEC 17025 General Requirements for the Competence of Test
12、ing and Calibration Laboratories2.3 Other Documents:4NIST Technical Note 1297 Guideline for Evaluating and Expressing the Uncertainty of NIST Measurement Results1This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of
13、Subcommittee D02.07 onFlow Properties.Current edition approved Oct. 1, 2010. Published November 2010. Originally approved in 2004. Last previous edition approved in 2004 as D704204.DOI:10.1520/D7042-10.on Flow Properties.Current edition approved Feb. 15, 2011. Published March 2011. Originally approv
14、ed in 2004. Last previous edition approved in 2010 as D704210. DOI:10.1520/D7042-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary
15、page on the 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 Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.1
16、This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior edi
17、tions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions:3.1.1 dynamic visc
18、osity (h), nthe ratio between the applied shear stress and rate of shear of a liquid.3.1.1.1 DiscussionIt is sometimes called the coefficient of dynamic viscosity or, simply, viscosity. Thus, dynamic viscosityis a measure of the resistance to flow or to deformation of a liquid under external shear f
19、orces.3.1.1.2 DiscussionThe term dynamic viscosity can also be used in a different context to denote a frequency-dependentquantity in which shear stress and shear rate have a sinusoidal time dependence.3.1.2 kinematic viscosity (n), nthe ratio of the dynamic viscosity (h) to the density (r) of a liq
20、uid.3.1.2.1 DiscussionFor gravity flow under a given hydrostatic head, the pressure head of a liquid is proportional to its density(r). Therefore the kinematic viscosity (n) is a measure of the resistance to flow of a liquid under gravity.3.1.3 density (r), nmass per unit volume.3.1.4 Relative densi
21、ty (also called specific gravity (SG), nthe ratio of the density of a material at a stated temperature to thedensity of a reference material (usually water) at a stated temperature.4. Summary of Test Method4.1 The test specimen is introduced into the measuring cells, which are at a closely controlle
22、d and known temperature. Themeasuring cells consist of a pair of rotating concentric cylinders and an oscillating U-tube. The dynamic viscosity is determinedfrom the equilibrium rotational speed of the inner cylinder under the influence of the shear stress of the test specimen and an eddycurrent bra
23、ke in conjunction with adjustment data. The density is determined by the oscillation frequency of the U-tube inconjunction with adjustment data. The kinematic viscosity is calculated by dividing the dynamic viscosity by the density.5. Significance and Use5.1 Many petroleum products, and some non-pet
24、roleum materials, are used as lubricants and the correct operation of theequipment depends upon the appropriate viscosity of the liquid being used. In addition, the viscosity of many petroleum fuels isimportant for the estimation of optimum storage, handling, and operational conditions. Thus, the ac
25、curate determination ofviscosity is essential to many product specifications.5.2 Density is a fundamental physical property that can be used in conjunction with other properties to characterize both thelight and heavy fractions of petroleum and petroleum products.5.3 Determination of the density or
26、relative density of petroleum and its products is necessary for the conversion of measuredvolumes to volumes at the standard temperature of 15C.6. Apparatus6.1 Stabinger Viscometer5,66.1.1 Viscosity measurementThe Stabinger viscometer uses a rotational coaxial cylinder measuring system. The outer cy
27、linder(tube) is driven by a motor at a constant and known rotational speed. The low-density inner cylinder (rotor) is held in the axis ofrotation by the centrifugal forces of the higher density sample and in its longitudinal position by the magnet and the soft iron ring.Consequently, the system work
28、s free of bearing friction as found in rotational viscometers. A permanent magnet in the innercylinder induces eddy currents in the surrounding copper casing. The rotational speed of the inner cylinder establishes itself as theresult of the equilibrium between the driving torque of the viscous force
29、s and the retarding eddy current torque. This rotationalspeed is measured by an electronic system (Hall effect sensor) by counting the frequency of the rotating magnetic field (see Fig.1 and Fig. 2, No. 2).6.1.2 Density MeasurementThe digital density analyzer uses a U-shaped oscillating sample tube
30、and a system for electronicexcitation and frequency counting (see Fig. 2, No. 3).6.1.3 Temperature ControlThe copper block surrounds both the viscosity and the density measuring cell in a way that bothcells are held at the same temperature. A thermoelectric heating and cooling system (see Fig. 2, No
31、. 1) ensures the temperaturestability of the copper block within 60.005C from the set temperature at the position of the viscosity cell over the wholetemperature range. The uncertainty (k = 2; 95 % confidence level) of the temperature calibration shall be no more than 60.03Cover the range from 15 to
32、 100C. Outside this range the calibration uncertainty shall be no more than 60.05C.6.1.4The thermal equilibration time depends on the heat capacity and conductivity of the liquid and on the difference betweeninjection temperature and test temperature. Adequate temperature equilibration of the test s
33、pecimen is automatically determinedwhen successive viscosity values are constant within 60.07% over 1 min and successive density values are constant within60.00003 g/mL over 1 min.5The Stabinger viscometer is covered by a patent. Interested parties are invited to submit information regarding the ide
34、ntification of an alternative to this patented itemto the ASTM International headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.6The sole source of supply of the apparatus known to the committee at this time is Ant
35、on Paar GmbH, Anton-Paar-Str. 20, A-8054 Graz, Austria. If you are aware ofalternative suppliers, please provide this information to ASTM International headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend.D7042 1126.1
36、.4 The thermal equilibration time depends on the heat capacity and conductivity of the liquid and on the difference betweeninjection temperature and test temperature. Adequate temperature equilibration of the test specimen is automatically determinedwhen successive viscosity values are constant with
37、in 60.07 % over 1 min and successive density values are constant within60.00003 g/cm3over 60 s.NOTE 1The Stabinger Viscometer, manufactured by Anton Paar GmbH, fulfills the stated requirements when operated in the most precise mode ofoperation.6.2 Syringes, commercially available, at least 5 mL in v
38、olume, with a Luer tip. All construction materials for syringes shall befully compatible with all sample liquids and cleaning agents, which contact them.6.3 Flow-Through or Pressure Adapter, for use as an alternative means of introducing the test specimen into the measuring cellseither by pressure o
39、r by suction, provided that sufficient care and control is used to avoid any bubble formation in the test specimen.All construction materials for adaptors shall be fully compatible with all sample liquids and cleaning agents, which contact them.6.4 Screen, with an aperture of 75 m, to remove particl
40、es from the sample.6.5 Magnet, strong enough to remove iron fillings from the sample. Magnetic stirring rods are suitable.7. Reagents and Materials7.1 Sample Solvent, completely miscible with the sample.7.1.1 For most samples, a volatile petroleum spirit or naphtha is suitable. If the solvent dries
41、up without residues in an applicabletime frame, the use of a separate drying solvent is not required.7.1.2 For residual fuels, a prewash with an aromatic solvent such as toluene or xylene may be necessary to remove asphalticmaterial.7.2 Drying Solvent, a volatile solvent miscible with the sample sol
42、vent (see 7.1).7.2.1 Highly concentrated ethanol (96 % or higher) is suitable.7.3 Dry Air or Nitrogen, for blowing the measuring cells.7.3.1 If the measuring cell temperature is below or near the dew point temperature of the ambient air, the use of an appropriatedesiccator is required.FIG. 1 Viscosi
43、ty CellFIG. 2 Cell BlockD7042 1138. Sampling, Test Specimens, and Test Units8.1 Sampling is defined as all the steps required to obtain an aliquot of the contents of any pipe, tank, or other system, and toplace the sample into the laboratory test container. The laboratory test container and sample v
44、olume shall be of sufficient capacityto mix the sample and obtain a homogeneous sample for analysis.8.2 ParticlesFor samples that are likely to contain particles (for example, used oils or crude oils) pass the sample through a75-m screen to remove the particles. For the removal of iron filings the u
45、se of a magnet is appropriate. Waxy samples must beheated to dissolve the wax crystals prior to filtration and a preheated filter shall be used.8.3 Test SpecimenA portion or volume of sample obtained from the laboratory sample and delivered to the measuring cells.The test specimen is obtained as fol
46、lows:8.3.1 Mix the sample, if required, to homogenize. Mixing at room temperature in an open container can result in the loss ofvolatile material; mixing in closed, pressurized containers, or at sub-ambient temperatures is recommended.8.3.2 Draw the test specimen from a properly mixed laboratory sam
47、ple using an appropriate syringe.Alternatively, if the properattachments and connecting tubes are used, the test specimen can be delivered directly to the measuring cells from the mixingcontainer. For waxy or other samples with a high pour point, before drawing the test specimen, heat the laboratory
48、 sample to thedesired test temperature, which has to be high enough to dissolve the wax crystals.9. Calibration and Verification9.1 Use only a calibrated apparatus as described in 6.1. The calibration shall be checked periodically using certified referencestandards as described in 9.2 and 9.3. The r
49、ecommended interval for viscosity and density calibration is once a month, fortemperature control once a year. For the calibration procedure follow the instructions of the manufacturer of the apparatus.9.2 Certified Viscosity and Density Reference StandardsThese are for use as confirmatory checks on the procedure in thelaboratory. Certified viscosity and density reference standards shall be certified by a laboratory, which has shown to meet therequirements of ISO/IEC 17025 or a corresponding national standard by independent assessment. Viscosity stand
