1、Designation: D 4741 06An American National StandardStandard Test Method forMeasuring Viscosity at High Temperature and High ShearRate by Tapered-Plug Viscometer1This standard is issued under the fixed designation D 4741; the number immediately following the designation indicates the year oforiginal
2、adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defens
3、e.1. Scope*1.1 This test method2covers the laboratory determination ofthe viscosity of oils at 150C and 1 3 106s1and at 100C and1 3 106s1, using high shear rate tapered-plug viscometermodels BE/C or BS/C.1.2 Newtonian calibration oils are used to adjust the work-ing gap and for calibration of the ap
4、paratus. These calibrationoils cover a range from approximately 1.8 to 5.9 mPa-s (cP) at150C and 4.2 to 18.9 mPa-s (cP) at 100C. This test methodshould not be used for extrapolation to higher viscosities thanthose of the Newtonian calibration oils used for calibration ofthe apparatus. If it is so us
5、ed, the precision statement will nolonger apply.1.3 A non-Newtonian reference oil is used to check that theworking conditions are correct. The exact viscosity appropriateto each batch of this oil is established by testing on a numberof instruments in different laboratories. The agreed value forthis
6、reference oil may be obtained from the chairman of theCoordinating European Council (CEC) Surveillance Group forCEC L-36-A90, or from the distributor.1.4 Applicability to products other than engine oils has notbeen determined in preparing this test method.1.5 This test method uses the millipascal se
7、conds, mPa-s, asthe unit of viscosity. For information, the equivalent cgs unit,centipoise, cP, is shown in parentheses.1.6 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-pr
8、iate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D91 Test Method for Precipitation Number of LubricatingOilsD 4683 Test Method for Measuring Viscosity at High ShearRate and High Temperature by Tapered
9、Bearing SimulatorD 5481 Test Method for Measuring Apparent Viscosity atHigh-Temperature and High-Shear Rate by Multicell Cap-illary Viscometer2.2 Coordinating European Council (CEC) Standard:4L36-A90 The Measurement of Lubricant Dynamic Viscos-ity under Conditions of High Shear (Ravenfield)2.3 Energ
10、y Institute:5IP 370 Test Method for the Measurement of LubricantDynamicViscosity Under Conditions of High Shear Usingthe Ravenfield Viscometer3. Terminology3.1 Definitions:3.1.1 apparent viscosity, nthe determined viscosity ob-tained by this test method.3.1.2 density, nthe mass per unit volume. In t
11、he SI, theunit of density is the kg/m3, but for practical use, a submultipleis more convenient.The g/cm3is 103kg/m3and is customarilyused.3.1.3 kinematic viscosity, nthe ratio of the viscosity to thedensity of a liquid. It is a measure of the resistance of flow ofa liquid under gravity. In the SI, t
12、he unit of kinematic viscosityis the metre squared per second; for practical use, a submultiple1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved May
13、1, 2006. Published May 2006. Originallyapproved in 1987. Last previous edition approved in 2000 as D 474100.2This test method is technically identical to that described in CEC L36A90(under the jurisdiction of the CEC Engine Lubricants Technical Committee) and inIP 370.3For referenced ASTM standards,
14、 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.4Available from Coordination European Council, Madou Plaza, 25th floor, PlaceMadou 1, B-1030
15、, Brussels, Belgium.5Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.(millimetre squared per
16、 second) is more convenient. Thecentistoke (cSt) is 1 mm2/s and is often used.3.1.4 Newtonian oil or fluid, nan oil or fluid, which at agiven temperature, exhibits a constant viscosity at all shearrates or shear stresses.3.1.5 non-Newtonian oil or fluid, nan oil or fluid thatexhibits a viscosity tha
17、t varies with changing shear stress orshear rate.3.1.6 shear rate, nthe velocity gradient in fluid flow. TheSI unit for shear rate is the reciprocal second (s1).3.1.7 shear stress, nthe motivating force per area for fluidflow. The area is the area of shear. In the SI, the unit for shearstress is the
18、 Pascal (Pa).3.1.8 viscosity, nthe ratio between the applied shear stressand rate of shear. It is sometimes called the coefficient ofdynamic viscosity. This coefficient is a measure of the resis-tance to flow of the liquid. In the SI, the unit of viscosity is thepascal second (Pa-s); for practical u
19、se, a submultiple, millipas-cal second (mPa-s), is more convenient. The centipoise (cP) is1 mPa-s and is commonly used.3.2 Definitions of Terms Specific to This Standard:3.2.1 calibration oils, nNewtonian oils used to establishthe reference framework of viscosity versus torque in thisinstrument from
20、 which the test oil viscosity is determined.3.2.2 non-Newtonian check oil, nnon-Newtonian oil usedto check that the gap or distance between the rotor and statorwill produce the desired operating shear rate of 1 3 106s1.3.2.2.1 DiscussionCheck oil is an acceptable name fornon-Newtonian reference oil.
21、3.2.3 test oil, nany oil for which apparent viscosity is tobe determined.4. Summary of Test Method4.1 The lubricant under test fills the annulus between aclose-fitting rotor and stator. The rotor and stator have a slight,matching taper to allow adjustment of the gap and hence theshear rate.The rotor
22、 is spun at a known speed, and the lubricantviscosity is determined from measurements of the reactiontorque by reference to a curve prepared using Newtoniancalibration oils.5. Significance and Use5.1 Viscosity measured under the conditions of this testmethod is considered to be representative of tha
23、t at thetemperatures and shear rates but not the pressures in the journalbearings of internal combustion engines under operating con-ditions.5.2 The relevance of these conditions to the measurement ofengine-oil viscosity has been discussed in many publications.66. Apparatus6.1 Tapered-Plug High Shea
24、r Rate Viscometer, Model BE/C(single speed) or BS/C (multi-speed). The viscometer uses arotating tapered plug in a matched stator.NOTE 1Model BE/C has a restricted torque range and may not becapable of measuring higher viscosities at 100C.6.2 Vacuum Extract Pipe, to ensure constant oil level. Theext
25、ract pipe is supplied with all current models.6.3 Calibration Weight (supplied with instrument).6.4 Thermostatically Controlled Heating Bath, with fluidcirculator. For acceptable temperature control and recoverytime, the temperature difference between the bath and mea-surement head should be targete
26、d at 4C and shall not exceed8C. This temperature difference is influenced by the natureand rate of flow of the circulating fluid; the length and bore ofthe heating pipes; and the viscosity of the bath fluid.NOTE 2Bath oil with kinematic viscosity not greater than 10 mm2/s at150C is recommended.6.5 A
27、 means of measuring temperature is not necessary forcurrent instruments since a precision temperature sensor is nowbuilt-in. For older instruments still in the field, a device with aprecision not worse than 60.20C is necessary.6.6 The use of an ultrasonic cleaner is recommended.6.7 The manufacturer
28、offers a package incorporating all theabove and including the necessary calibration oils, referenceoils, and bath oil.6.8 Vacuum Pump, with suitable liquid trap.7. Materials7.1 Newtonian Calibration Oils7CEC Reference Oils RL102, RL 103, RL 104, RL 105, RL 106, and RL 107.7.2 Non-Newtonian Reference
29、 Oil7CEC Reference OilRL 174.7.3 Washing SolventASTM precipitation naphtha asspecified in Test Method D91 or a suitable replacementsolvent. (WARNINGExtremely flammable. Vapors maycause flash fire. See Annex A1.)7.4 Flushing SolventWhile spirit or Stoddard solvent.8. Sampling8.1 Test oils that are vi
30、sually free from haze and particulatesneed not be filtered before evaluation.Asample shall be free ofparticles larger than 3m. If heavy concentration of smallerparticles is still visible after filtration through a filter of poresize 3m, it is recommended to reduce their concentration byfurther filtr
31、ation. This will reduce the possibility of the par-ticles wedging in the measurement gap and so causing erosionof the rotor/stator or erroneous readings. Do not filter formu-lated oils through pore sizes below 1 m because certainlubricant additives may be removed.8.2 Used oils may also be tested in
32、these instruments,though no precision statement is available for these materials.8.2.1 Filter used oils through a suitable filter such asWhatman GF/C fibreglass filter. The process of filtration isgreatly accelerated by either warming or applying pressure.Procedures shall be such that all risk of pa
33、rticulate contamina-tion is avoided.NOTE 3Suggestions have been made that the process of filtration may6For a comprehensive review, see “The Relationship Between High-Temperature Oil Rheology and Engine Operation,” ASTM Data Series Publication62 (out of print).7Under the jurisdiction of CEC Engine L
34、ubricants Technical Committee.Ravenfield Designs Limited are distributors.D4741062itself cause a change of viscosity by the removal of particles. No doubt ifthere is a very heavy concentration of particles greater than 3 m, this willbe so. It is not expected or intended that this test method will be
35、 used forsuch oils. Evidence to date is that filtration of used oils from normalengines in normal periods of use is acceptable. It is, however, advisable touse pressure filtration rather than vacuum filtration so that volatilecomponents will not be removed. No precision statement is available foruse
36、d oils.9. Initial Preparation of Apparatus9.1 These instructions relate to instruments incorporating acomputer, in other words, Models BE/C and BS/C. Changesfrom earlier editions of this test method are those given in10.1.5, 10.5.1, 10.5.2, 11.1.2, and 11.1.3 and the use of avacuum extract pipe to e
37、nsure constant oil level (see 6.2).9.2 Set up the apparatus in accordance with the manufac-turers manual. Attach the funnel to the side arm, using therubber sleeve provided.NOTE 4The funnel has a larger bore than stock funnels in order toincrease the rate of flow of oil samples.9.3 It is recommended
38、 that the instrument is NOT mountedin a fume cupboard since this draws in dirt particles. Localextraction over the heating bath is all that is necessary since themanufacturers bath is practically sealed.9.4 When setting up the apparatus, a torque calibration shallbe performed following the instructi
39、ons in the manufacturersmanual.9.5 The instrument is supplied by the manufacturer with allother functions already calibrated and set up. It is recom-mended that these other initial settings be accepted untilsufficient familiarity is obtained with the use of the apparatus.When it is desired to modify
40、 the initial settings, full instruc-tions will be found in the manufacturers manual.9.6 It is advisable to gain access to the list of calibration oilsheld in the memory of the instrument in order to be familiarwith its contents and to check that it is in accordance with thestandards actually supplie
41、d.9.7 Preparation of Apparatus on All Other Occasions:9.7.1 Turn on the heating bath.9.7.2 Flush out the measurement chamber using washingsolvent.9.7.3 Refill the measurement chamber with Reference OilRL 174.9.7.4 Leave for not less than half an hour for temperature tostabilise.9.7.4.1 If the bath d
42、oes not reach correct temperature in thistime, then either extend this period or, preferably, address theproblem of why heating is slow.10. Procedure10.1 Outline of Method:10.1.1 The lubricant under test fills the annulus between aclose-fitting rotor and stator. The rotor and stator have agradual ma
43、tching taper to allow adjustment of the gap andhence the shear rate. Spin the rotor at a known speed anddetermine the lubricant viscosity from measurements of thereaction torque by reference to a line prepared using Newto-nian calibration oils.10.1.2 Use Newtonian calibration oils to adjust the work
44、inggap and for calibration of the apparatus. These calibration oilscover a range from approximately 1.8 to 5.9 mPa-s (cP) at150C and 4.2 to 18.9 mPa-s (cP) at 100C. The test methodshould not be used for extrapolation to higher or lowerviscosities than those of the Newtonian calibration oils used for
45、calibration of the apparatus (see 1.1).10.1.3 Use a non-Newtonian reference oil to check that theworking conditions are correct. The agreed value for thisreference oil may be obtained from the Chair of CEC Surveil-lance Group SL-036 on Method L-36, or from the distributor.410.1.4 Use six Newtonian c
46、alibration oils to prepare atorque versus viscosity calibration. Perform a linear regressionto obtain a measure of the fit of the calibration result to a truestraight line and of the intercept of torque offset on the zeroviscosity line.10.1.5 The correlation coefficient is defined in Annex A2and sha
47、ll be calculated to five decimal places and shall be notless than 0.99970. The torque offset is a useful indication of thequality of a rotor and stator and its state of running-in. Torqueoffset may be used as a laboratory quality control parameter.10.1.6 When a satisfactory correlation coefficient h
48、as beenobtained, measure the non-Newtonian reference oil. This oilshall also be used after every three to six test measurements tomaintain a continuous check on the correct functioning of theinstrument.10.1.7 The initial measured value for reference oil shall beequal to its value as stated by the ma
49、nufacturer within 60.04mPa-s at 150C and within 60.06 mPa-s at 100C. Subsequentmeasured values for reference oil shall be equal to its value asstated by the manufacturer within 60.06 mPa-s, providing it isnot in the opposite direction from the initial deviation fromnominal.10.1.8 If at any point the check oil measured value fallsoutside the acceptable limits, discard all test oil values deter-mined since the last successful check oil value and remeasure,following an acceptable check oil determination.10.1.9 Take readings at the point of t
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1