ASTM_D_6895_-_06_2012.pdf

Designation:D689506(Reapproved 2012)Standard Test Method forRotational Viscosity of Heavy Duty Diesel Drain Oils at100C1This standard is issued under the fixed designation D6895;the number immediately following the designation indicates the year 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 the determination of the rota-tional viscosity and the shear thinning properties of heavy dutydiesel engine drain oils at 100C,in the shear rate range ofapproximately 10 to 300 s-1,in the shear stress range ofapproximately 0.1 to 10 Pa and the viscosity range of approxi-mately 12 to 35 mPas.Rotational viscosity values can becompared at a shear rate of 100 s-1by this test method.2,31.2 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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:4D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5967 Test Method for Evaluation of Diesel Engine Oils inT-8 Diesel EngineD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 maximum point timeinstrument setting that limitsthe amount of time the instrument will maintain a constantshear stress or shear rate before accepting the value as theequilibrium value.3.1.2 rate indexthe exponent,c,in these expressionsrelating shear rate and shear stress:shear stress5 bshear rate!c(1)lnshear stress!5 lnb1clnshear rate!(2)3.1.2.1 DiscussionA rate index of c=1 signifies Newto-nian fluid behavior.Values less than one indicate increasingnon-Newtonian,shear thinning behavior.33.1.3 rotational viscositythe viscosity obtained by use ofthis test method.3.1.4 VIS100 DECrotational viscosity at shear rate of 100s-1,decreasing shear stress or shear rate sweep.3.1.5 VIS100 INCrotational viscosity at shear rate of 100s-1,increasing shear stress or shear rate sweep.4.Summary of Test Method4.1 The sample is placed in a controlled stress or controlledshear rate rheometer/viscometer at 100C.The sample ispresheared at 10 s-1for 30 s followed by heating at 100C for10 min.An increasing shear rate(approximately 10 to 300 s-1)or shear stress(0.1 to 10 Pa)sweep is run followed by adecreasing sweep.The rotational viscosity for each step(increasing and decreasing)at 100 s-1shear rate is interpolatedfrom the viscosity versus shear rate data table.The rate index,as a measure of shear thinning,is calculated from a plot of ln(shear stress)versus ln(shear rate).5.Significance and Use5.1 Rotational viscosity measurements allow the determina-tion of the non-Newtonian,shear thinning property of drain oil.Rotational viscosity values can be compared at a shear rate of100 s-1by this test method.2,36.Apparatus6.1 This test method uses rheometers/viscometers of thecontrolled stress or controlled rate mode of operation.The testmethod requires the use of concentric cylinder measuringgeometry or cone and plate measuring geometries,with a1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 2003.Last previous edition approved in 2006 as D689506.DOI:10.1520/D6895-06R12.2Selby,K.,“Rheology of Sootthickened Diesel Engine Oils,”SAE 981369,May 1998.3George,H.F.,Bardasz,E.A.,and Soukup,B.,“Understanding SMOT throughDesigned Experimentation Part 3:An Improved approach to Drain Oil ViscosityMeasurementsRotational Rheology,”SAE 97692,May 1997.4For referenced ASTM standards,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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 minimum cone diameter of 50 mm,capable of operating in therange of approximately 0.1 to 10 Pa for shear stress and 10 to300 s-1for shear rate.6.2 Instrument data logging or software shall be capable ofdelivering shear stress versus shear rate data and viscosityversus shear rate data in tabular form.During the experiment,a minimum of 20 points must be taken.The method for datalogging shall be an equilibrium method where the controlledstress or controlled rate value is held constant until the datapoint equilibrium is reached.The use of a maximum point timeis acceptable,but it must be set to at least 30 s.6.3 Temperatu