ASTM_D_3829_-_14.pdf

Designation:D382914Standard Test Method forPredicting the Borderline Pumping Temperature of EngineOil1This standard is issued under the fixed designation D3829;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.Scope*1.1 This test method covers the prediction of the borderlinepumping temperature(BPT)of engine oils through the use ofa 16 h cooling cycle over the temperature range from 0 C to40 C.The precision is stated for temperatures from 34 C to15 C.1.2 Applicability to petroleum products other than engineoils has not been determined.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 ExceptionThis test method uses the SI based unit ofmilliPascal second(mPas)for viscosity,which is equivalent tocentipoise(cP).1.4 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:E563 Practice for Preparation and Use of an Ice-Point Bathas a Reference TemperatureE644 Test Methods for Testing Industrial Resistance Ther-mometersE1137 Specification for Industrial Platinum Resistance Ther-mometersE2877 Guide for Digital Contact Thermometers2.2 ISO Standards:2ISO 17025 General Requirements for the Competence ofTesting and Calibration LaboratoriesISO Guide 34 General Requirements for the Competence ofReference Material Producers3.Terminology3.1 Definitions:3.1.1 apparent viscosity,nthe determined viscosity ob-tained by use of this test method.3.1.2 Digital Contact Thermometer(DCT),nan electronicdevice consisting of a digital display and associated tempera-ture sensing probe.3.1.2.1 DiscussionThis device consists of a temperaturesensor connected to a measuring instrument;this instrumentmeasures the temperature-dependent quantity of the sensor,computes the temperature from the measured quantity,andprovides a digital output,or display of the temperature,or both.This device is sometimes referred to as a digital thermometer.NOTE1Portable electronic thermometers(PET)is an acronym some-times used to refer to a subset of the devices covered by this definition.3.1.3 Newtonian oil or fluid,nan oil or fluid that at a giventemperature exhibits a constant viscosity at all shear rates orshear stresses.3.1.4 non-Newtonian oil or fluid,nan oil or fluid that at agiven temperature exhibits a viscosity that varies with chang-ing shear stress or shear rate.3.1.5 shear rate,nthe velocity gradient in fluid flow.Fora Newtonian fluid in a concentric cylinder rotary viscometer inwhich the shear stress is measured at the inner cylinder surface(such as the apparatus being described),and ignoring any endeffects,the shear rate is given as follows:52Rs2Rs22 Rr2!(1)54Rs2tRs22 Rr2!(2)where:=shear rate at the surface of the rotor in reciprocalseconds,s1,=angular velocity,rad/s,Rs=stator radius,mm,Rr=rotor radius,mm,andt=time in seconds for one revolution of the rotor.1This 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 July 1,2014.Published August 2014.Originallyapproved in 1979.Last previous edition approved in 2012 as D3829 12.DOI:10.1520/D3829-14.2Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*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 States1 For the specific apparatus being described in 6.1.1,563t(3)3.1.6 shear stress,nthe motivating force per unit area forfluid flow.Area is the area under shear.For the rotaryviscometer being described,the rotor surface is the area undershear.Tr5 9.81MRo1Rt!31026(4)5Tr2 Rr2h3109(5)where:Tr=torque applied to rotor,Nm,M=applied mass,g,Ro=radius of the shaft,mm,Rt=radius of the thread,mm,=shear stress at the rotor surface,Pa,andh=height of the rotor,mm.For the dimensions given in 6.1.1,Tr5 31.7M 31026(6)5 3.5M(7)3.1.7 viscosity,nthe ratio between the applied shear stressand rate of shear.It is sometimes called the coefficient ofdynamic viscosity.This value is thus a measure of theresistance to flow of the liquid.The SI unit of viscosity is thepascal second(Pas).3.2 Definitions of Terms Specific to This Standard:3.2.1 borderline pumping temperature,nthe maximumtemperature at which the critical yield stress or critical viscos-ity occurs,whichever is the higher temperature.3.2.2 calibration oils,ntho