1、Designation: D4741 12D4741 13Standard Test Method forMeasuring Viscosity at High Temperature and High ShearRate by Tapered-Plug Viscometer1This standard is issued under the fixed designation D4741; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test
3、 method2 covers the laboratory determination of the viscosity of oils at 150C150 C and 1 106s1 and at100C100 C and 1 106s1, using high shear rate tapered-plug viscometer models BE/C or BS/C.1.2 Newtonian calibration oils are used to adjust the working gap and for calibration of the apparatus. These
4、calibration oilscover a range from approximately 1.81.4 mPas to 5.9 mPa-smPas (cP) at 150C150 C and 4.24.2 mPas to 18.9 mPa-smPas (cP)at 100C.100 C.This test method should not be used for extrapolation to higher viscosities than those of the Newtonian calibrationoils used for calibration of the appa
5、ratus. If it is so used, the precision statement will no longer apply. The precision has only beendetermined for the viscosity range 1.48 mPas to 5.07 mPas at 150 C and from 4.9 mPas to 11.8 mPas at 100 C for the materialslisted in the precision section.1.3 A non-Newtonian reference oil is used to c
6、heck that the working conditions are correct. The exact viscosity appropriate toeach batch of this oil is established by testing on a number of instruments in different laboratories. The agreed value for thisreference oil may be obtained from the chairman of the Coordinating European Council (CEC) S
7、urveillance Group for CECL-36-A90, or from the distributor.1.4 Applicability to products other than engine oils has not been determined in preparing this test method.1.5 This test method uses the millipascal seconds, mPa-s,mPas, as the unit of viscosity. For information, the equivalent cgs unit,cent
8、ipoise, cP, is shown in parentheses.1.6 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 determine the applicability of regulatorylimita
9、tions prior to use.2. Referenced Documents2.1 ASTM Standards:3D91 Test Method for Precipitation Number of Lubricating OilsD4683 Test Method for MeasuringViscosity of New and Used Engine Oils at High Shear Rate and HighTemperature byTaperedBearing Simulator Viscometer at 150 CD5481 Test Method for Me
10、asuring Apparent Viscosity at High-Temperature and High-Shear Rate by Multicell CapillaryViscometerD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsD6708 Practice for Statistical Assessment and Improvement of Expected Agreement
11、Between Two Test Methods that Purportto Measure the Same Property of a Material2.2 Coordinating European Council (CEC) Standard:4L36-A90 The Measurement of Lubricant Dynamic Viscosity under Conditions of High Shear (Ravenfield)1 This test method is under the jurisdiction of ASTM Committee D02 on Pet
12、roleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved Nov. 1, 2012Oct. 1, 2013. Published February 2013November 2013. Originally approved in 1987. Last previous edition approved in 20062012as D4741D47
13、41 12.06. DOI: 10.1520/D4741-12.10.1520/D4741-13.2 This test method is technically identical to that described in CEC L36A90 (under the jurisdiction of the CEC Engine Lubricants Technical Committee) and in IP 370.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Cus
14、tomer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 Available from CEC Secretariat, Interlynk Administrative Services, Ltd., Lynk House, 17 Peckleton Lane, Desford, Leicestershire, LE9 9JU, United K
15、ingdom.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 pr
16、ior editions as appropriate. In all cases only 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 19
17、428-2959. United States12.3 Energy Institute:5IP370 Test Method for the Measurement of Lubricant Dynamic Viscosity Under Conditions of High Shear Using the RavenfieldViscometer3. Terminology3.1 Definitions:3.1.1 apparent viscosity, nthe determined viscosity obtained viscosity of a non-Newtonian liqu
18、id determined by this testmethod.method at a particular shear rate and shear stress.3.1.2 density, nthe mass per unit volume. In the SI, the unit of density is the kg/mvolume of the test3, but for practical use,a submultiple is more convenient. The g/cm liquid at a given temperature. 3 is 103 kg/m3
19、and is customarily used.3.1.2.1 DiscussionIn SI notation, the unit of density is the kilogram per cubic metre. However, for practical use, gram per cubic centimetre iscustomarily used and is equivalent to 103kg/m3.3.1.3 kinematic viscosity, nthe ratio of the viscosity (dynamic, absolute) to the dens
20、ity of athe liquid. It is a measure of theresistance ofto flow of a liquid under gravity. In the SI, the unit of kinematic viscosity is the metre squared per second; for practicaluse, a submultiple (millimetre squared per second) is more convenient. The centistoke (cSt) is 1 mmwhere the shear stress
21、 (forcecausing flow) is applied by gravity. Kinematic viscosity values are thus affected by both the dynamic viscosity (absolute viscosity)of the liquid 2/s and is often used.and its density.3.1.3.1 DiscussionIn SI, the unit of kinematic viscosity is the metre squared per second, often conveniently
22、expressed as millimetre squared persecond and termed the centiStoke.3.1.4 Newtonian oil or fluid,liquid, nan oil or fluid, whichliquid that at a given temperature,temperature exhibits a constantviscosity at all shear rates orand shear stresses.3.1.5 non-Newtonian oil or fluid,liquid, nan oil or flui
23、dliquid that exhibits a viscosity that varies with changing shear stressorand shear rate.3.1.6 shear rate, nthe velocity gradient in fluid flow. The SI liquid flow in millimetres per second per millimetre (mm/s permm) resulting from applied shear stress; the System International (SI) unit for shear
24、rate is the reciprocal second (sseconds, s 1-1)3.1.7 shear stress, nthe motivating force per area for fluid flow. The area is the area of shear. In the unit area causing liquidflow over the area where viscous shear is being caused; in SI, the unit forof shear stress is the Pascal (Pa).3.1.8 viscosit
25、y, nthe ratio between the of applied shear stress and the resulting rate of shear. It is sometimes called thecoefficient of dynamic viscosity. This coefficient dynamic or absolute viscosity (in contrast to kinematic viscosity, see 3.1.3).Viscosity is a measure of the resistance to flow of the liquid
26、. In the SI, the unit of viscosity is the pascal second (Pa-s); for practicaluse, a submultiple, millipascal second (mPa-s), is more convenient. The centipoise (cP) is 1 mPa-s and is commonly used.liquidat a given temperature.3.1.8.1 DiscussionIn SI, the unit of viscosity is the Pascalsecond (Pas),
27、often conveniently expressed as milliPascalsecond (mPas), which has theEnglish system equivalent of the centipoise (cP).3.2 Definitions of Terms Specific to This Standard:3.2.1 calibration oils, nNewtonian oils used to establish the reference framework of viscosity versus torque in this instrumentfr
28、om which the test oil viscosity is determined.3.2.2 non-Newtonian check oil, nnon-Newtonian oil used to check that the gap or distance between the rotor and stator willproduce the desired operating shear rate of 1 106 s1.3.2.2.1 DiscussionCheck oil is an acceptable name for non-Newtonian reference o
29、il.5 Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K.D4741 1323.2.3 test oil, nany oil for which apparent viscosity is to be determined.4. Summary of Test Method4.1 The lubricant under test fills the annulus between a close-fitting rotor and stator. The rotor and stator h
30、ave a slight, matchingtaper to allow adjustment of the gap and hence the shear rate. The rotor is spun at a known speed, and the lubricant viscosity isdetermined from measurements of the reaction torque by reference to a curve prepared using Newtonian calibration oils.5. Significance and Use5.1 Visc
31、osity measured under the conditions of this test method is considered to be representative of that at the temperaturesand shear rates but not the pressures in the journal bearings of internal combustion engines under operating conditions.5.2 The relevance of these conditions to the measurement of en
32、gine-oil viscosity has been discussed in many publications.66. Apparatus6.1 Tapered-Plug High Shear 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 be capable o
33、f measuring higher viscosities at 100C.100 C.6.2 Vacuum Extract Pipe, to ensure constant oil level. The extract pipe is supplied with all current models.6.3 Calibration Weight (supplied with instrument).6.4 Thermostatically Controlled Heating Bath, with fluid circulator. For acceptable temperature c
34、ontrol and recovery time, thetemperature difference between the bath and measurement head should be targeted at 4C4 C and shall not exceed 8C.8 C. Thistemperature difference is influenced by the nature and rate of flow of the circulating fluid; the length and bore of the heating pipes;and the viscos
35、ity of the bath fluid.NOTE 2Bath oil with kinematic viscosity not greater than 10 mm2/s at 150C150 C is recommended.6.5 A means of measuring temperature is not necessary for current instruments since a precision temperature sensor is nowbuilt-in. For older instruments still in the field, a device wi
36、th a precision not worse than 60.20C60.20 C is necessary.6.6 The use of an ultrasonic cleaner is recommended.6.7 The manufacturer offers a package incorporating all the above and including the necessary calibration oils, reference oils,and bath oil.6.8 Vacuum Pump, with suitable liquid trap.7. Mater
37、ials7.1 Newtonian Calibration Oils7CEC Reference Oils RL 102, RL 103, RL 104, RL 105, RL 106, and RL 107. CannonCertified Viscosity Reference Standard HT22 (nominal viscosity of 1.5 mPas at 150 C).7.2 Non-Newtonian Reference Oil7CEC Reference Oil RL 232.7.3 Washing SolventASTM precipitation naphtha
38、as specified in Test Method D91 or a suitable replacement solvent.(WARNING Extremely flammable. Vapors may cause flash fire. See Annex A1.)7.4 Flushing SolventWhile spirit or Stoddard solvent.8. Sampling8.1 Test oils that are visually free from haze and particulates need not be filtered before evalu
39、ation. A sample shall be free ofparticles larger than 3m.3 m. If heavy concentration of smaller particles is still visible after filtration through a filter of pore size3m,3 m, it is recommended to reduce their concentration by further filtration. This will reduce the possibility of the particleswed
40、ging in the measurement gap and so causing erosion of the rotor/stator or erroneous readings. Do not filter formulated oilsthrough pore sizes below 1 m because certain lubricant additives may be removed.8.2 Used oils may also be tested in these instruments, though no precision statement is available
41、 for these materials.8.2.1 Filter used oils through a suitable filter such as Whatman GF/C fibreglass filter. The process of filtration is greatlyaccelerated by either warming or applying pressure. Procedures shall be such that all risk of particulate contamination is avoided.NOTE 3Suggestions have
42、been made that the process of filtration may itself cause a change of viscosity by the removal of particles. No doubt if thereis a very heavy concentration of particles greater than 3 m, this will be so. It is not expected or intended that this test method will be used for such oils.Evidence to date
43、 is that filtration of used oils from normal engines in normal periods of use is acceptable. It is, however, advisable to use pressure filtration6 For a comprehensive review, see “The Relationship Between High-Temperature Oil Rheology and Engine Operation,” ASTM Data Series Publication 62 (out of pr
44、int).7 Under the jurisdiction of CEC Engine Lubricants Technical Committee. Ravenfield Designs Limited are distributors.D4741 133rather than vacuum filtration so that volatile components will not be removed. No precision statement is available for used oils.9. Initial Preparation of Apparatus9.1 The
45、se instructions relate to instruments incorporating a computer, in other words, Models BE/C and BS/C. Changes fromearlier editions of this test method are those given in 10.1.5, 10.5.1, 10.5.2, 11.1.2, and 11.1.3 and the use of a vacuum extract pipeto ensure constant oil level (see 6.2).9.2 Set up t
46、he apparatus in accordance with the manufacturers manual. Attach the funnel to the side arm, using the rubbersleeve provided.NOTE 4The funnel has a larger bore than stock funnels in order to increase the rate of flow of oil samples.9.3 It is recommended that the instrument is NOTmounted in a fume cu
47、pboard since this draws in dirt particles. Local extractionover the heating bath is all that is necessary since the manufacturers bath is practically sealed.9.4 When setting up the apparatus, a torque calibration shall be performed following the instructions in the manufacturersmanual.9.5 The instru
48、ment is supplied by the manufacturer with all other functions already calibrated and set up. It is recommendedthat these other initial settings be accepted until sufficient familiarity is obtained with the use of the apparatus. When it is desiredto modify the initial settings, full instructions will
49、 be found in the manufacturers manual.9.6 It is advisable to gain access to the list of calibration oils held in the memory of the instrument in order to be familiar withits contents and to check that it is in accordance with the standards actually supplied.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 washing solvent.9.7.3 Refill the measurement chamber with Reference Oil RL 232.9.7.4 Leave for not less than half a
