1、Designation: D4741 06D4741 12Standard 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 150C and 1 106s1 and at 100C and 1 10 6s1, 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 calibrat
4、ion oilscover a range from approximately 1.8 to 5.9 mPa-s (cP) at 150C and 4.2 to 18.9 mPa-s (cP) at 100C. This test method shouldnot be used for extrapolation to higher viscosities than those of the Newtonian calibration oils used for calibration of the apparatus.If it is so used, the precision sta
5、tement will no longer apply.1.3 A non-Newtonian reference oil is used to check 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
6、be obtained from the chairman of the Coordinating European Council (CEC) Surveillance 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, as
7、 the 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 the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and
8、 health practices and determine the applicability of regulatorylimitations 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 b
9、yTaperedBearing Simulator Viscometer at 150 CD5481 Test Method for Measuring Apparent Viscosity at High-Temperature and High-Shear Rate by Multicell CapillaryViscometer2.2 Coordinating European Council (CEC) Standard:4L36-A90 The Measurement of Lubricant Dynamic Viscosity under Conditions of High Sh
10、ear (Ravenfield)2.3 Energy Institute:5IP370 Test Method for the Measurement of Lubricant Dynamic Viscosity Under Conditions of High Shear Using the RavenfieldViscometer1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibi
11、lity of Subcommittee D02.07 onFlow Properties.Current edition approved May 1, 2006Nov. 1, 2012. Published May 2006February 2013. Originally approved in 1987. Last previous edition approved in 20002006 asD474100.06. DOI: 10.1520/D4741-06.10.1520/D4741-12.2 This test method is technically identical to
12、 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 Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to
13、 the standards Document Summary page on the ASTM website.4 Available from Coordination European Council, Madou Plaza, 25th floor, Place Madou 1, B-1030, Brussels, Belgium.CEC Secretariat, InterlynkAdministrative Services,Ltd., Lynk House, 17 Peckleton Lane, Desford, Leicestershire, LE9 9JU, United K
14、ingdom.5 Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K.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 a
15、dequately depict all changes accurately, ASTM recommends that users consult prior 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 AS
16、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions:3.1.1 apparent viscosity, nthe determined viscosity obtained by this test method.3.1.2 density, nthe mass per unit volume. In the SI, the unit of density is the kg/m3,
17、but for practical use, a submultiple is moreconvenient. The g/cm3 is 103 kg/m3 and is customarily used.3.1.3 kinematic viscosity, nthe ratio of the viscosity to the density of a liquid. It is a measure of the resistance of flow of aliquid under gravity. In the SI, the unit of kinematic viscosity is
18、the metre squared per second; for practical use, a submultiple(millimetre squared per second) is more convenient. The centistoke (cSt) is 1 mm 2/s and is often used.3.1.4 Newtonian oil or fluid, nan oil or fluid, which at a given temperature, exhibits a constant viscosity at all shear rates orshear
19、stresses.3.1.5 non-Newtonian oil or fluid, nan oil or fluid that exhibits a viscosity that varies with changing shear stress or shear rate.3.1.6 shear rate, nthe velocity gradient in fluid flow. The SI unit for shear rate is the reciprocal second (s 1).3.1.7 shear stress, nthe motivating force per a
20、rea for fluid flow. The area is the area of shear. In the SI, the unit for shear stressis the Pascal (Pa).3.1.8 viscosity, nthe ratio between the applied shear stress and rate of shear. It is sometimes called the coefficient of dynamicviscosity. This coefficient is a measure of the resistance to flo
21、w of the liquid. In the SI, the unit of viscosity is the pascal second(Pa-s); for practical use, a submultiple, millipascal second (mPa-s), is more convenient. The centipoise (cP) is 1 mPa-s and iscommonly used.3.2 Definitions of Terms Specific to This Standard:3.2.1 calibration oils, nNewtonian oil
22、s used to establish the reference framework of viscosity versus torque in this instrumentfrom 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
23、of 1 106 s 1.3.2.2.1 DiscussionCheck oil is an acceptable name for non-Newtonian reference oil.3.2.3 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 sta
24、tor have 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
25、 Viscosity 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
26、of engine-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 capa
27、ble of measuring higher viscosities at 100C.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 co
28、ntrol and recovery time, thetemperature difference between the bath and measurement head should be targeted at 4C and shall not exceed 8C. 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 viscosity of t
29、he bath fluid.NOTE 2Bath oil with kinematic viscosity not greater than 10 mm2/s at 150C is recommended.6 For a comprehensive review, see “The Relationship Between High-Temperature Oil Rheology and Engine Operation,” ASTM Data Series Publication 62 (out of print).D4741 1226.5 A means of measuring tem
30、perature is not necessary for current instruments since a precision temperature sensor is nowbuilt-in. For older instruments still in the field, a device with a precision not worse than 60.20C is necessary.6.6 The use of an ultrasonic cleaner is recommended.6.7 The manufacturer offers a package inco
31、rporating all the above and including the necessary calibration oils, reference oils,and bath oil.6.8 Vacuum Pump, with suitable liquid trap.7. Materials7.1 Newtonian Calibration Oils7CEC Reference Oils RL 102, RL 103, RL 104, RL 105, RL 106, and RL 107.7.2 Non-Newtonian Reference Oil7CEC Reference
32、Oil RL 174. 232.7.3 Washing Solvent ASTM precipitation naphtha 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 Solvent While spirit or Stoddard solvent.8. Sampling8.1 Test oils that are visually f
33、ree from haze and particulates need not be filtered before evaluation. A sample shall be free ofparticles larger than 3m. If heavy concentration of smaller particles is still visible after filtration through a filter of pore size 3m,it is recommended to reduce their concentration by further filtrati
34、on. This will reduce the possibility of the particles wedging inthe measurement gap and so causing erosion of the rotor/stator or erroneous readings. Do not filter formulated oils through poresizes below 1 m because certain lubricant additives may be removed.8.2 Used oils may also be tested in these
35、 instruments, though no precision statement is available 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 part
36、iculate contamination is avoided.NOTE 3Suggestions have 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
37、 test method will be used for such oils.Evidence to date is that filtration of used oils from normal engines in normal periods of use is acceptable. It is, however, advisable to use pressure filtrationrather than vacuum filtration so that volatile components will not be removed. No precision stateme
38、nt is available for used oils.9. Initial Preparation of Apparatus9.1 These 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
39、a vacuum extract pipeto ensure constant oil level (see 6.2).9.2 Set up the 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 samp
40、les.9.3 It is recommended that the instrument is NOTmounted in a fume cupboard 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 perfor
41、med following the instructions in the manufacturersmanual.9.5 The instrument 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.
42、When it is desiredto modify the initial settings, full instructions will 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 th
43、e 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 174.232.9.7.4 Leave for not less than half an hour for temperature
44、 to stabilise.9.7.4.1 If the bath does not reach correct temperature in this time, then either extend this period or, preferably, address theproblem of why heating is slow.7 Under the jurisdiction of CEC Engine Lubricants Technical Committee. Ravenfield Designs Limited are distributors.D4741 12310.
45、Procedure10.1 Outline of Method:10.1.1 The lubricant under test fills the annulus between a close-fitting rotor and stator. The rotor and stator have a gradualmatching taper to allow adjustment of the gap and hence the shear rate. Spin the rotor at a known speed and determine the lubricantviscosity
46、from measurements of the reaction torque by reference to a line prepared using Newtonian calibration oils.10.1.2 Use Newtonian calibration oils to adjust the working gap and for calibration of the apparatus.These calibration oils covera range from approximately 1.8 to 5.9 mPa-s (cP) at 150C and 4.2
47、to 18.9 mPa-s (cP) at 100C. The test method should not beused for extrapolation to higher or lower viscosities than those of the Newtonian calibration oils used for calibration of theapparatus (see 1.1).10.1.3 Use a non-Newtonian reference oil to check that the working conditions are correct. The ag
48、reed value for this referenceoil may be obtained from the Chair of CEC Surveillance Group SL-036 on Method L-36, or from the distributor.410.1.4 Use six Newtonian calibration oils to prepare a torque versus viscosity calibration. Perform a linear regression to obtaina measure of the fit of the calib
49、ration result to a true straight line and of the intercept of torque offset on the zero viscosity line.10.1.5 The correlation coefficient is defined in AnnexA2 and shall be calculated to five decimal places and shall be not less than0.99970. The torque offset is a useful indication of the quality of a rotor and stator and its state of running-in. Torque offset maybe used as a laboratory quality control parameter.10.1.6 When a satisfactory correlation coefficient has been obtained, measure the non-Newtonian reference oil. This o
