1、Designation: D3829 14Standard 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 rev
2、ision. 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 coo
3、ling 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 in
4、cluded 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
5、 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
6、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 Comp
7、etence 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
8、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
9、 sometimes referred to as a digital thermometer.NOTE 1Portable 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 she
10、ar 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 i
11、nwhich 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,
12、 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.Cur
13、rent 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
14、 Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1For the specific apparatus being described in 6.1.1, 563t(3)3.1.6 shear stress, nthe motivating force per unit area forfluid flow. Are
15、a 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 surfa
16、ce, 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 th
17、e 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,
18、nthose oils for establishing theinstruments reference framework of apparent viscosity versusspeed from which the apparent viscosities of test oils aredetermined.3.2.3 critical viscosity, nthe maximum viscosity at adefined shear rate to allow adequate flow of oil to the oil pumpin an automotive engin
19、e.Ahigher viscosity can cause failure tomaintain adequate oil pressure through the limiting of flowthrough the oil screen or oil inlet tubes.3.2.4 critical yield stress, nthe maximum yield stress thatallows oil to flow to the inlet oil screen in an automotiveengine. With a higher yield stress, air m
20、ay be drawn into thepump and cause failure to maintain adequate oil pressurethrough air-binding of the pump.3.2.5 test oil, nany oil for which the apparent viscosityand yield stress are to be determined by use of the test methodunder description.3.2.6 yield stress, nthe shear stress required to init
21、iateflow. For all Newtonian fluids and some non-Newtonian fluids,yield stress is zero. Some engine oils have a yield stress that isa function of their low-temperature cooling rate, soak time, andtemperature.4. Summary of Test Method4.1 An engine oil sample is cooled from 80 C to the desiredtest temp
22、erature at a nonlinear programmed cooling rate over a10 h period and held at the test temperature for the remainderof a 16 h period. After completion of the soak period, twostandard torques of increasing severity are applied to the rotorshaft and the speed of rotation in each case is measured. Fromt
23、he results at three or more temperatures, the borderlinepumping temperature is determined.4.2 Alternatively, for some specification or classificationpurposes it may be sufficient to determine that the BPT is lessthan a certain specified temperature.5. Significance and Use5.1 Borderline pumping tempe
24、rature is a measure of thelowest temperature at which an engine oil can be continuouslyand adequately supplied to the oil pump inlet of an automotiveengine.6. Apparatus6.1 Mini-Rotary Viscometer,3consisting of one or more vis-cometric cells including a calibrated rotor-stator assembly,which are cont
25、ained in a temperature-controlled aluminumblock.6.1.1 The viscometric cell has the following nominal di-mensions:Diameter of rotor 17.06 mm 0.08 mmLength of rotor 20.00 mm 0.14 mmInside of diameter of cup 19.07 mm 0.08 mmRadius of shaft 3.18 mm 0.13 mmRadius of string 0.1 mm6.2 Weights:6.2.1 Yield S
26、tress MeasurementA set of nine disks and adisk holder, each with a mass of 10 g 6 0.1 g.6.2.2 Viscosity MeasurementWeight with mass of 150 g 61.0 g.6.3 Temperature Measuring DeviceUse either a DCTmeeting the requirements described in 6.3.1 or liquid-in-glassthermometers as described in 6.3.2. A cali
27、brated DCT orcalibrated low temperature liquid-in-glass thermometer shallbe used as the thermometer for temperature measurementbelow 25 C independent of the instruments temperaturecontrol, and shall be located in the thermowell.NOTE 2The display device and sensor must be correctly paired.Incorrect p
28、airing will result in temperature measurement errors andpossibly irreversible damage to the electronics of the display.6.3.1 Digital contact thermometer requirements:Criteria Minimum RequirementsDCT E2877 Class BTemperature range 45 C to 100 CDisplay resolution 0.1 C minimum, preferably 0.01 CSensor
29、 type RTD, such as a PRT or thermistorSensor,metal sheathed3 mm O.D. with an sensing element less than30 mm in length to be used with a thermowellsleeve, 6 mm O.D. 58 mm long with a 3mm hole in center.Sensor,glass sheathed6 mm O.D. with a sensing element less than12 mm in length3The sole source of s
30、upply of the apparatus known to the committee at this timeis Cannon Instrument Co., P.O. Box 16, State College, PA 16801. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of ther
31、esponsible technical committee,1which you may attend.D3829 142Display accuracy 50 mK (0.05 C) for combined probe andsensorResponse time less than or equal to 25 s as defined inSpecification E1137Drift less than 50 mK (0.05 C) per yearCalibration Error less than 50 mK (0.05 C) over the range ofintend
32、ed use.Calibration Range 40 C to 85 CCalibration Data 4 data points evenly distributed over therange of 40 C to 1 C and included in cali-bration report.Calibration Report From a calibration laboratory with demon-strated competency in temperature calibrationwhich is traceable to a national calibratio
33、nlaboratory or metrology standards bodyNOTE 3With respect to DCT probe immersion depth, a procedure todetermine minimum depth can be found in Guide E2877, Section 5.3, orTest Methods E644, Section 7.6.3.1.1 The DCT calibration drift shall be checked at leastannually by either measuring the ice point
34、 or against areference thermometer in a constant temperature bath at theprescribed immersion depth to ensure compliance with 6.3.1.With respect to an ice bath, Practice E563 provides guidanceon the preparation and use of an ice bath. However, for this use,variance from the specific steps, such as wa
35、ter source, ispermitted provided preparation is consistent. The basis for thevariance is due to the reference being used to track change incalibration not verification.NOTE 4When a DCTs calibration drifts in one direction over severalcalibration checks, that is, ice point, it may be an indication of
36、 deteriora-tion of the DCT.6.3.2 For liquid-in-glass, LiG, thermometers, two are re-quired. One LiG shall be a calibrated 76 mm partial immersionthermometer with a scale from +5 C to 1 degree less than thelowest test temperature in 0.2 C subdivisions. This lowtemperature LiG thermometer shall have a
37、 report of calibrationshowing the temperature deviation at each calibrated testtemperature. The second LiG thermometer shall be a 76 mmpartial immersion thermometer graduated from at least +70 Cto 90 C in 1 C subdivisions, which is used to verify thepreheat temperature.6.3.2.1 Calibration CheckVerif
38、y the low temperaturethermometer at least annually against a reference thermometerin a constant temperature bath or an ice bath. The thermometeris to be inserted to its immersion depth. If using an ice bath, theice point reading is to be taken within 60 min after thethermometer has been at test temp
39、erature for at least 3 min. Ifthe corrected temperature reading deviates from the referencethermometer or the ice point then repeat this calibration check.If the thermometer deviates from the reference value on twosuccessive checks then a full thermometer recalibration isneeded.6.3.2.2 Recalibration
40、A complete recalibration of theliquid-in-glass thermometer, while permitted, is not necessaryin order to meet the accuracy ascribed to liquid-in-glassthermometers design until the thermometers corrected mea-sured temperature deviates from the reference thermometer orice point by one scale division,
41、or until five years has elapsedsince the last full calibration.6.4 Temperature Control SystemRegulates the mini-rotaryviscometer block temperature in accordance with the tempera-ture requirements described in Table X1.1.6.5 Cell CapA cover inserted into the top of the viscom-eter cell to minimize ro
42、om air circulation into the cells isrequired for thermoelectrically cooled instruments. The cellcap is a stepped cylinder 38 mm 6 1 mm in length made of alow thermal conductivity material, for example, thermoplasticsuch as acetyl copolymers that have known solvent resistivityand are suitable for use
43、 between the temperature ranges of thistest method. The top half is 28 mm 6 1 mm in diameter and thebottom half is 19 mm in diameter with a tolerance consistentwith the cell diameter. The tolerance on the bottom half is suchthat it will easily fit into cell but not allow the cap to contact therotor
44、shaft. The piece has a center bore of 11 mm 6 1 mm. Thecap is made in two halves to facilitate placement in the top ofthe cell.6.5.1 Cell caps shall not be used in the direct refrigerationinstruments, since such use would block the flow of cold, dryair into the stators to keep them frost-free.6.6 Su
45、pply of Dry GasA supply of dry filtered dry gas tominimize moisture condensation on the upper portions of theinstrument.6.6.1 For thermoelectric cooled instruments, which use cellcaps, the dry gas supply is connected to the housing cover. Thesupply of dry gas is discontinued when the cover is remove
46、dfor the measurement phase of the test.6.7 Locking PinA device to keep the rotor from turningprematurely and able to stop the rotor at the nearest halfrevolution by interaction with the rotor crossbar.7. Reagents and Materials7.1 Low Cloud-Point, Newtonian Oil,3a calibration oil ofapproximately 30 P
47、as viscosity at 20 C for calibration of theviscometric cells. The calibration oil shall be obtained fromsuppliers complying with ISO Guide 34 and ISO 17025 withtraceability to a national metrology institute (NMI).7.2 Methanol, commercial or technical grade of dry metha-nol is suitable for the coolin
48、g bath.7.3 Oil Solvent, commercial heptanes or similar solvent issuitable.7.4 Acetone, technical grade of acetone is suitable providedit does not leave a residue upon evaporation.8. Sampling8.1 A representative sample of test oil free from suspendedsolid material and water is necessary to obtain val
49、id results. Ifthe sample in its container is received below the dew-pointtemperature of the room, allow to warm to room temperaturebefore opening.9. Calibration and Standardization9.1 Temperature Control Calibration ProcedureCalibratethe MRV temperature control by comparing the instrumentsdisplayed temperature against a thermometer in the thermow-ell. The thermometer used shall meet the requirements in 6.3.9.1.1 Place 10 mL of a typical test fluid and rotor in eachcell. If required, pl
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