1、Designation: D7042 163D7042 163Standard 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 oforigina
2、l 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 NOTEThe title of Table X3.2 was corrected editorially in July 2016.2 NOTETab
3、les 2 and 3 were corrected editorially in September 2016.3 NOTESubsection 15.4.5 and footnote 12 were corrected editorially in December 2016.1. Scope*1.1 This test method covers and specifies a procedure for the concurrent measurement of both the dynamic viscosity, , and thedensity, , of liquid petr
4、oleum products and crude oils, both transparent and opaque. The kinematic viscosity, , can be obtainedby dividing the dynamic viscosity, , by the density, , obtained at the same test temperature.1.2 The result obtained from this test method is dependent upon the behavior of the sample and is intende
5、d for application toliquids for which primarily the shear stress and shear rate are proportional (Newtonian flow behavior).1.3 The precision has only been determined for those materials, viscosity ranges, density ranges, and temperatures as indicatedin Section 15 on Precision and Bias. The test meth
6、od can be applied to a wider range of materials, viscosity, density, andtemperature. For materials not listed in Section 15 on Precision and Bias, the precision and bias may not be applicable.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included
7、 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 safety and health practices and to determine the applicability of regulatorylimitations prior to
8、use.2. Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)D975 Specification for Diesel Fuel OilsD2162 Practice for Basic Calibration of Master Viscometers and Viscos
9、ity Oil StandardsD2270 Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 C and 100 CD4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to E
10、valuate Analytical Measure-ment 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 for Statistical Assess
11、ment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a MaterialD6751 Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate FuelsD7467 Specification for Diesel Fuel Oil, Biodiesel Blend (B6 to B20)2.2 ISO Standards:3ISO 57
12、25 Accuracy (Trueness and Precision) of Measurement Methods and ResultsISO 8217 Specifications for Marine Fuels1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properti
13、es.Current edition approved May 15, 2016. Published June 2016. Originally approved in 2004. Last previous edition approved in 2014 as D7042 14. DOI:10.1520/D7042-16E02.DOI:10.1520/D7042-16E03.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serv
14、iceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard an
15、d 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 editions as appropriate. In all cases only
16、the current versionof the standard as published by ASTM is to be considered the official document.*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 States1ISO/IEC 17025 General R
17、equirements for the Competence of Testing and Calibration Laboratories2.3 Other Documents:4NIST Technical Note 1297 Guideline for Evaluating and Expressing the Uncertainty of NIST Measurement Results3. Terminology3.1 Definitions:3.1.1 density (), nmass per unit volume.3.1.2 dynamic viscosity (), nth
18、e ratio between the applied shear stress and rate of shear of a liquid.3.1.2.1 DiscussionIt is sometimes called the coefficient of dynamic viscosity or, simply, viscosity. Thus, dynamic viscosity is a measure of theresistance to flow or to deformation of a liquid under external shear forces.3.1.2.2
19、DiscussionThe term dynamic viscosity can also be used in a different context to denote a frequency-dependent quantity in which shear stressand shear rate have a sinusoidal time dependence.3.1.3 kinematic viscosity (), nthe ratio of the dynamic viscosity () to the density () of a liquid.3.1.3.1 Discu
20、ssionFor gravity flow under a given hydrostatic head, the pressure head of a liquid is proportional to its density (). Therefore thekinematic viscosity () is a measure of the resistance to flow of a liquid under gravity.3.1.4 relative density (also called specific gravity (SG), nthe ratio of the den
21、sity 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 controlled and known temperature. Themeasuring cells consist of a pai
22、r 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 brake in conjunction with adjustment data. The density is deter
23、mined 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-petroleum materials, are used as lubricants and the correct ope
24、ration 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 accurate determination ofviscosity is essential to many produc
25、t 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 relative density of petroleum and its products is necessary
26、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 cylinder(tube) is driven by a motor at a constant and known rot
27、ational speed. The low-density inner cylinder (rotor) is held in the axis of4 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.5 The Stabinger viscometer is covered by a patent. Interested parties are inv
28、ited to submit information regarding the identification 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.6 The sole source of supply of the apparat
29、us known to the committee at this time is Anton 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
30、 committee, which you may attend.D7042 1632rotation 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 works free of bearing friction as found in rotational viscometers. A permanent magnet in the inner
31、cylinder 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 forces and the retarding eddy current torque. This rotationalspeed is measured by an electronic sys
32、tem (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 and a system for electronicexcitation and frequency counting (see Fig. 2, No. 3).6.1.3 Tempera
33、ture 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. 1) ensures the temperaturestability of the copper block within 60.005 C from the set tempera
34、ture 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 60.03 Cover the range from 15 C to 100 C. Outside this range the calibration uncertainty shall be no more than 60.05 C.6.1.4
35、 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 within
36、 60.07 % over 1 min and successive density values are constant within60.00003 g/cm3 over 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 vo
37、lume, 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 or
38、 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 Hot Filling Adapter, for use with manual syringe fil
39、ling for the purpose of preventing the precipitation of waxy componentsdissolved in sample and lowering sample viscosity for 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 the tes
40、tspecimen prior to and during the analysis and be equipped to transfer a representative portion of test specimen into the measuringcells. The autosampler shall transfer the test specimen from the sample vial to the measuring cells of the apparatus withoutinterfering with the integrity of the test sp
41、ecimen. The autosampler shall be able to mimic the procedure for sample handling asset forth in 11.1 and 11.2. The autosampler may have heating capability as a means to prevent the precipitation of waxycomponents dissolved in the sample and lower the viscosity of the sample for filling the measuring
42、 cells.6.6 Screen, with an aperture of 75 m, to remove particles from the sample.6.7 Magnet, strong enough to remove iron fillings from the sample. Magnetic stirring rods are suitable.6.8 Ultrasonic Bath, Unheated (optional), with an operating frequency between 25 kHz to 60 kHz and a typical power o
43、utputof 100 W, of suitable dimensions to hold container(s) placed inside of bath, for use in effectively dissipating and removing airor gas bubbles that can be entrained in viscous sample types prior to analysis. It is permissible to use ultrasonic baths with operatingfrequencies and power outputs o
44、utside this range, however it is the responsibility of the laboratory to conduct a data comparisonstudy to confirm that results determined with and without the use of such ultrasonic baths does not materially impact results.7. Reagents and Materials7.1 Sample Solvent, completely miscible with the sa
45、mple.FIG. 1 Viscosity CellD7042 16337.1.1 For most samples, a volatile petroleum spirit or naphtha is suitable. If the solvent dries 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
46、as toluene or xylene may be necessary to remove asphalticmaterial.7.2 Drying Solvent, a volatile solvent miscible with the sample solvent (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 temp
47、erature is below or near the dew point temperature of the ambient air, the use of an appropriatedesiccator is required.8. Sampling, Test Specimens, and Test Units8.1 General Considerations and Guidelines:8.1.1 Sampling is defined as all the steps required to obtain an aliquot of the contents of any
48、pipe, tank, or other system, andto place the sample into the laboratory test container. The laboratory test container and sample volume shall be of sufficientcapacity to mix the sample and obtain a homogeneous sample for analysis.8.1.2 For some sample types, such as viscous lube oils that are prone
49、to having entrained air or gas bubbles present in thesample, the use of an ultrasonic bath (see 6.8) without the heater turned on (if so equipped), has been found effective in dissipatingbubbles typically within 1 min.8.1.3 ParticlesFor samples that are likely to contain particles (for example, used oils or crude oils) pass the sample througha 75 m screen to remove the particles. For the removal of iron filings the use of a magnet is appropriate. Waxy samples must beheated to dissolve the wax crystals prior to filtration and a preh
