1、Designation: D3829 14D3829 17Standard 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
2、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 borderline pumping temperature (BPT) of engine oils through the use of
3、a 16 hcooling cycle over the temperature range from 0 C to 40 C. The precision is stated for temperatures from 34 C to 15 C.1.2 Applicability to petroleum products other than engine oils has not been determined.1.3 The values stated in SI units are to be regarded as standard. No other units of measu
4、rement are included in this standard.1.3.1 ExceptionThis test method uses the SI based unit of milliPascal second (mPas) for viscosity, which is equivalent tocentipoise (cP).1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsib
5、ilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Dec
6、ision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:E563 Practice for Preparation and Use of an Ice-Point Bath as a Reference Tempera
7、tureE644 Test Methods for Testing Industrial Resistance ThermometersE1137 Specification for Industrial Platinum Resistance ThermometersE2877 Guide for Digital Contact Thermometers2.2 ISO Standards:2ISO 17025 General Requirements for the Competence of Testing and Calibration Laboratories1 This test m
8、ethod is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved July 1, 2014May 1, 2017. Published August 2014May 2017. Originally approved in 1979. Last previo
9、us edition approved in 20122014 asD3829 12.D3829 14. DOI: 10.1520/D3829-14.10.1520/D3829-17.2 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provide the user
10、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 prior editions as appropriate. In all cases only the current versionof the standard as p
11、ublished 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 19428-2959. United States1ISO Guide 34 General Requirements for the Competence of Refere
12、nce Material Producers3. Terminology3.1 Definitions:3.1.1 apparent viscosity, nthe determined viscosity obtained by use of this test method.3.1.2 Digital Contact Thermometerdigital contact thermometer (DCT), nan electronic device consisting of a digital displayand associated temperature sensing prob
13、e.3.1.2.1 DiscussionThis device consists of a temperature sensor connected to a measuring instrument; this instrument measures the temperature-dependent quantity of the sensor, computes the temperature from the measured quantity, and provides a digital output, or displayof the temperature, or both.
14、This device is output. This digital output goes to a digital display and/or recording device that maybe internal or external to the device. These devices are sometimes referred to as a“digital digital thermometer.thermometers.”NOTE 1Portable electronic thermometers (PET) is an acronym sometimes used
15、 to refer to a subset of the devices covered by this definition.3.1.2.2 DiscussionPET is an acronym for portable electronic thermometers, a subset of digital contact thermometers (DCT).3.1.3 Newtonian oil or fluid, nan oil or fluid that at a given temperature exhibits a constant viscosity at all she
16、ar rates or shearstresses.3.1.4 non-Newtonian oil or fluid, nan oil or fluid that at a given temperature exhibits a viscosity that varies with changingshear stress or shear rate.3.1.5 shear rate, nthe velocity gradient in fluid flow. For a Newtonian fluid in a concentric cylinder rotary viscometer i
17、n whichthe shear stress is measured at the inner cylinder surface (such as the apparatus being described), and ignoring any end effects, theshear rate is given as follows: 5 2Rs2Rs22R r2! (1) 5 4piRs2tRs22Rr2! (2)where: = shear rate at the surface of the rotor in reciprocal seconds, s1, = angular ve
18、locity, rad/s,Rs = stator radius, mm,Rr = rotor radius, mm, andt = time in seconds for one revolution of the rotor.For the specific apparatus being described in 6.1.1, 563t (3)3.1.6 shear stress, nthe motivating force per unit area for fluid flow. Area is the area under shear. For the rotary viscome
19、terbeing described, the rotor surface is the area under shear.Tr59.81MRo1Rt!31026 (4) 5 Tr2piRr2h 3109 (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
20、 the dimensions given in 6.1.1,Tr 531.7M 31026 (6)D3829 172 53.5M (7)3.1.7 viscosity, nthe ratio between the applied shear stress and rate of shear. It is sometimes called the coefficient of dynamicviscosity. This value is thus a measure of the resistance to flow of the liquid. The SI unit of viscos
21、ity is the pascal second (Pas).3.2 Definitions of Terms Specific to This Standard:3.2.1 borderline pumping temperature, nthe maximum temperature at which the critical yield stress or critical viscosityoccurs, whichever is the higher temperature.3.2.2 calibration oils, nthose oils for establishing th
22、e instruments reference framework of apparent viscosity versus speedfrom which the apparent viscosities of test oils are determined.3.2.3 critical viscosity, nthe maximum viscosity at a defined shear rate to allow adequate flow of oil to the oil pump in anautomotive engine. A higher viscosity can ca
23、use failure to maintain adequate oil pressure through the limiting of flow through theoil screen or oil inlet tubes.3.2.4 critical yield stress, nthe maximum yield stress that allows oil to flow to the inlet oil screen in an automotive engine.With a higher yield stress, air may be drawn into the pum
24、p and cause failure to maintain adequate oil pressure through air-bindingof the pump.3.2.5 test oil, nany oil for which the apparent viscosity and yield stress are to be determined by use of the test method underdescription.3.2.6 yield stress, nthe shear stress required to initiate flow. For all New
25、tonian fluids and some non-Newtonian fluids, yieldstress is zero. Some engine oils have a yield stress that is a 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 desired test temperature at a nonlin
26、ear programmed cooling rate over a10 h period and held at the test temperature for the remainder of a 16 h period. After completion of the soak period, two standardtorques of increasing severity are applied to the rotor shaft and the speed of rotation in each case is measured. From the resultsat thr
27、ee or more temperatures, the borderline pumping temperature is determined.4.2 Alternatively, for some specification or classification purposes it may be sufficient to determine that the BPT is less than acertain specified temperature.5. Significance and Use5.1 Borderline pumping temperature is a mea
28、sure of the lowest temperature at which an engine oil can be continuously andadequately supplied to the oil pump inlet of an automotive engine.6. Apparatus6.1 Mini-Rotary Viscometer,3consisting of one or more viscometric cells including a calibrated rotor-stator assembly, which arecontained in a tem
29、perature-controlled aluminum block.6.1.1 The viscometric cell has the following nominal dimensions: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 Stress Measurem
30、entA set of nine disks and a disk holder, each with a mass of 10 g 6 0.1 g.6.2.2 Viscosity MeasurementWeight with mass of 150 g 6 1.0 g.6.3 Temperature Measuring DeviceUse either a DCT meeting the requirements described in 6.3.1 or liquid-in-glassthermometers as described in 6.3.2. A calibrated DCT
31、or calibrated low temperature liquid-in-glass thermometer shall be used asthe thermometer for temperature measurement below 25 C independent of the instruments temperature control, and shall belocated in the thermowell.NOTE 1The display device and sensor must be correctly paired. Incorrect pairing w
32、ill result in temperature measurement errors and possiblyirreversible damage to the electronics of the display.6.3.1 Digital contact thermometer requirements:3 The sole source of supply of the apparatus known to the committee at this time is Cannon Instrument Co., P.O. Box 16, State College, PA 1680
33、1. If you are aware ofalternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1 which you may attend.D3829 173Criteria Minimum RequirementsDCT E2877 Class BTemperatu
34、re range 45 C to 100 CDisplay resolution 0.1 C minimum, preferably 0.01 CSensor type RTD, such as a PRT or thermistorSensor,metal sheathed3 mm O.D. with an sensing element less than 30 mm in length to be used with a thermowellsleeve, 6 mm O.D. 58 mm long with a 3 mm hole in center.Sensor,glass sheat
35、hed6 mm O.D. with a sensing element less than 12 mm in lengthDisplay accuracy 50 mK (0.05 C) for combined probe and sensorResponse time less than or equal to 25 s as defined in Specification E1137Drift less than 50 mK (0.05 C) per yearCalibration Error less than 50 mK (0.05 C) over the range of inte
36、nded use.Calibration Range 40 C to 85 CCalibration Data 4 data points evenly distributed over the range of 40 C to 1 C and included in calibrationreport.Calibration Report From a calibration laboratory with demonstrated competency in temperature calibration which istraceable to a national calibratio
37、n laboratory or metrology standards bodyNOTE 2With respect to DCT probe immersion depth, a procedure to determine minimum depth can be found in Guide E2877, Section 5.3, or TestMethods E644, Section 7.6.3.1.1 The DCT calibration drift shall be checked at least annually by either measuring the ice po
38、int or against a referencethermometer in a constant temperature bath at the prescribed immersion depth to ensure compliance with 6.3.1. With respect toan ice bath, Practice E563 provides guidance on the preparation and use of an ice bath. However, for this use, variance from thespecific steps, such
39、as water source, is permitted provided preparation is consistent. The basis for the variance is due to thereference being used to track change in calibration not verification.NOTE 3When a DCTs calibration drifts in one direction over several calibration checks, that is, ice point, it may be an indic
40、ation of deteriorationof the DCT.6.3.2 For liquid-in-glass, LiG, thermometers, two are required. One LiG shall be a calibrated 76 mm partial immersionthermometer with a scale from +5 C to 1 degree less than the lowest test temperature in 0.2 C subdivisions. This low temperatureLiG thermometer shall
41、have a report of calibration showing the temperature deviation at each calibrated test temperature. Thesecond LiG thermometer shall be a 76 mm partial immersion thermometer graduated from at least +70 C to 90 C in 1 Csubdivisions, which is used to verify the preheat temperature.6.3.2.1 Calibration C
42、heckVerify the low temperature thermometer at least annually against a reference thermometer in aconstant temperature bath or an ice bath. The thermometer is to be inserted to its immersion depth. If using an ice bath, the icepoint reading is to be taken within 60 min after the thermometer has been
43、at test temperature for at least 3 min. If the correctedtemperature reading deviates from the reference thermometer or the ice point then repeat this calibration check. If the thermometerdeviates from the reference value on two successive checks then a full thermometer recalibration is needed.6.3.2.
44、2 RecalibrationA complete recalibration of the liquid-in-glass thermometer, while permitted, is not necessary in orderto meet the accuracy ascribed to liquid-in-glass thermometers design until the thermometers corrected measured temperaturedeviates from the reference thermometer or ice point by one
45、scale division, or until five years has elapsed since the last fullcalibration.6.4 Temperature Control SystemRegulates the mini-rotary viscometer block temperature in accordance with the temperaturerequirements described in Table X1.1.6.5 Cell CapA cover inserted into the top of the viscometer cell
46、to minimize room air circulation into the cells is required forthermoelectrically cooled instruments. The cell cap is a stepped cylinder 38 mm 6 1 mm in length made of a low thermalconductivity material, for example, thermoplastic such as acetyl copolymers that have known solvent resistivity and are
47、 suitablefor use between the temperature ranges of this test method. The top half is 28 mm 6 1 mm in diameter and the bottom half is 19mm in diameter with a tolerance consistent with the cell diameter. The tolerance on the bottom half is such that it will easily fitinto cell but not allow the cap to
48、 contact the rotor shaft. The piece has a center bore of 11 mm 6 1 mm. The cap is made in twohalves to facilitate placement in the top of the cell.6.5.1 Cell caps shall not be used in the direct refrigeration instruments, since such use would block the flow of cold, dry air intothe stators to keep t
49、hem frost-free.6.6 Supply of Dry GasA supply of dry filtered dry gas to minimize moisture condensation on the upper portions of theinstrument.6.6.1 For thermoelectric cooled instruments, which use cell caps, the dry gas supply is connected to the housing cover. Thesupply of dry gas is discontinued when the cover is removed for the measurement phase of the test.6.7 Locking PinA device to keep the rotor from turning prematurely and able to stop the rotor at the nearest half revolutionby
