1、Designation: D2532 10D2532 14Standard Test Method forViscosity and Viscosity Change After Standing at LowTemperature of Aircraft Turbine Lubricants1This standard is issued under the fixed designation D2532; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope
3、*1.1 This test method covers the determination of the kinematic viscosity of aircraft turbine lubricants at low temperature, andthe percent change of viscosity after a 3-h3 h and a 72-h72 h standing period at low temperature.1.1.1 The range of kinematic viscosities covered by this test method is fro
4、m 7700 mm2/s to 14 000 mm2/s at 40 C and from7000 mm2/s to 17 500 mm2/s at 51 C. The precision has only been determined for those materials, kinematic viscosity ranges,and temperatures as shown in the precision section. Kinematic viscosities and percent change of viscosity may be measured andreporte
5、d at other temperatures and other thermal soak period intervals as agreed by the contracting parties.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.2.1 The SI units unit used in this test method for Kinematic Viscosity
6、areis mm2/s. For user reference, 1 mm2/s = 10-6 m2/s= 1 cSt.1.3 WARNINGMercury has been designated by many regulatory agencies as a hazardous material that can cause centralnervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Cautions
7、hould be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet(MSDS) for details and EPAs websitehttp:/www.epa.gov/mercury/faq.htmfor additional information. Users should be awarethat selling mercury and/or mercury containing products into
8、 your state or country may be prohibited by law.1.4 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 health practices and determine the applicability of regu
9、latorylimitations prior to use. For specific hazard statements, see Section 67.2. Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)D446 Specifications and Operating Instructions for Glass Capillar
10、y Kinematic ViscometersD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsE1 Specification for ASTM Liquid-in-Glass ThermometersE563 Practice for Preparation and Use of an Ice-Point Bath as a Reference TemperatureE644 Test Methods
11、 for Testing Industrial Resistance ThermometersE1137 Specification for Industrial Platinum Resistance ThermometersE1750 Guide for Use of Water Triple Point CellsE2593 Guide for Accuracy Verification of Industrial Platinum Resistance ThermometersE2877 Guide for Digital Contact Thermometers2.2 Other D
12、ocuments:MIL-PRF-7808 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base3MIL-PRF-23699 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base, NATO Code Number O-15631 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is t
13、he direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved July 1, 2010Dec. 1, 2014. Published July 2010February 2015. Originally approved in 1966. Last previous edition approved in 20032010 asD2532D2532 10.03. DOI: 10.1520/D2532-10.10.1520/D2532-14.2 For referencedAS
14、TM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section
15、 D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.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 adequatel
16、y 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 ASTM Inter
17、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions:3.1.1 digital contact thermometer (DCT), nan electronic device consisting of a digital display and associated temperaturesensing probe.4. Summary of Test Method4.1 Kinematic vi
18、scosity is measuredand percent change is determined at low temperature in accordance with using apparatusdefined in Test Method D445 and Specifications D446 at time intervals of 3 h and 72 h.72 h following an initial measurement at35 min.NOTE 1This test method was developed and the precision establi
19、shed on tests at 53.9C (65F). It is also applied at 40C (40F) and may beused at other temperatures. Viscosities may be measured and reported at other intervals as agreed by the contracting parties.5. Significance and Use5.1 Aircraft turbine lubricants, upon standing at low temperatures for prolonged
20、 periods of time, may show an increase inkinematic viscosity. This increase may cause lubrication problems in aircraft engines. Thus, this test method is used to ensure thatthe kinematic viscosity does not exceed the maximum kinematic viscosity in certain specifications for aircraft turbine lubrican
21、ts.6. Apparatus6.1 Viscometers, drying tubes, low-temperature bath, thermometer, timer, secondary viscosity standard, filter, and cleaningsupplies are described in detail in Test Method D445.6.2 ViscometerThe viscometer shall meet the requirements of Test Method D445 and Specifications D446 and be o
22、f the typein which the sample can be rerun without cleaning the viscometer. Suitable holders should be used. For convenience it isrecommended that the viscometer size be chosen to keep the efflux time between 200200 s and 1000 s.1000 s.NOTE 1Consult Specifications D446 regarding calibration constant
23、 correction for the actual test temperature when using Specifications D446viscometers that are not suspended level types.6.3 Drying TubesFit the viscometer openings with drying tubes filled with indicating silica gel, using cotton at top and bottomto hold the loosely packed desiccant in place. Provi
24、de a cross-connection on the viscometer side of the drying tubes (which canbe closed by a pinch clamp or stopcock while liquid is being drawn into the efflux bulb) so that the restriction to air flow will notcause error. Replace the silica gel when a lavender color is noticeable.6.4 Viscosity Temper
25、ature BathThe constant-temperature bath must be capable of holding several viscometers at once. It musthave adequate stirring of the liquid medium (Note 2) and balance between heat losses such that the bath temperature can bemaintained at the required temperature 60.03C (60.05F).60.03 C.NOTE 2Isopro
26、panol or other clear, low-freezing point liquid may be used as a bath liquid.5.5 Low-Temperature Storage CabinetIf it is desired to exercise the option described in Note 3 (7.4), a low-temperaturestorage cabinet or bath shall be provided which is capable of holding the required temperature with a va
27、riation not to exceed60.3C (60.5F).6.5 Bath ThermometerTemperature Measuring DeviceCalibrated Use either a digital contact thermometer as described in6.5.2 with equal or better accuracy or a calibratedASTM Kinematic Viscosity Test Thermometer such as 73F or 74F 73C (40 C)or 74C or 43C (51 C) conform
28、ing to the requirements as prescribed in Specification E1. Other calibrated thermometric devicesare permissible provided their accuracy, precision, and sensitivity are equal to or better than the above thermometers. which havean accuracy after correction of 60.03 C or better.TheASTM 74C thermometer
29、has a specification between 55.4 C and 52.6 Cbut is available from some suppliers with the scale expanded to cover 51 C. The 43C thermometer is only graduated in 0.1 Cincrements so interpretation at midpoints between the lines may be required.6.5.1 When using liquid-in-glass thermometers, use a magn
30、ifying device to read the thermometer to the nearest 15 division (forexample, 0.02 C on thermometers graduated in 0.1 C increments) to ensure that the required test temperature and temperaturecontrol capabilities are met.6.5.1.1 Check the thermometers ice point at least annually using an ice bath or
31、 a constant temperature bath against a referencethermometer. If the corrected temperature reading error is greater than the temperature tolerance, then the thermometer must berecalibrated.6.5.2 When using a digital contact thermometer (DCT), the following requirements shall apply:Criteria Minimum Re
32、quirementsDCT E2877 Class ADisplay resolution 0.01 C, recommended 0.001 CDisplay accuracy 30 mK (0.03 C) for combined probe andsensorSensor type RTD, such as a PRT or thermistorDrift less than 10 mK (0.01 C) per yearD2532 142Criteria Minimum RequirementsResponse time less than or equal to 6 s as def
33、ined inSpecification E1137Linearity 10 mK over range of intended useCalibration Report The DCT shall have a report of temperaturecalibration traceable to a national calibrationor metrology standards body issued by acompetent calibration laboratory with demon-strated competency in temperature calibra
34、-tion. An ISO 17025 accredited laboratory withtemperature calibration in its accreditationscope would meet this requirement.Calibration Data The calibration report shall include at least 3calibration temperatures at least 5 C apartwhich are appropriate for its intended use.6.5.2.1 For a constant tem
35、perature bath employed, the DCT probe shall be immersed by more than its minimum immersiondepth in a constant temperature bath so that the center of the probes sensing region is at the same level as the lower half of theworking capillary provided the probes minimum immersion depth is met and is no l
36、ess than indicated on the calibration certificate.The end of the probe sheath shall not extend past the bottom of the viscometer. It is preferable for the center of the sensing elementto be located at the same level as the lower half of the working capillary as long as the minimum immersion requirem
37、ents are met.NOTE 3With respect to DCT probe immersion depth, a procedure is available in Test Methods E644, Section 7 (Minimum Immersion Length Test),for determining the minimum depth. With respect to an ice bath, Practice E563 provides guidance on the preparation of an ice bath, however variancefr
38、om the specific steps is permitted provided preparation is consistent as it is being used to track change in calibration.6.5.2.2 Verify the DCT calibration at least annually. The probe shall be recalibrated when the check value differs by more than0.01 C from the last probe calibration. Verification
39、 can be accomplished with the use of a water triple point cell, an ice bath, orother suitable constant temperature device which has a known temperature value of suitable precision. See Practice E563, GuideE1750, and Guide E2593 for more information regarding checking calibrations.6.5.2.3 In the case
40、 of constant temperature baths used in instruments for automatic viscosity determinations, the user is tocontact the instrument manufacturer for the correct DCT that has performance equivalence to that described here.6.6 Timing DeviceUse any timing device, spring-wound or digital, that is capable of
41、 taking readings with a discrimination of0.1 s or better and has an accuracy within 60.07 % (see Annex A3 of Test Method D445) of the reading when tested over theminimum and maximum intervals of expected flow times.6.6.1 Timing devices powered by alternating electric current may be used if the curre
42、nt frequency is controlled to an accuracyof 0.05 % or better. Alternating currents, as provided by some public power systems, are intermittently rather than continuouslycontrolled. When used to actuate electrical timing devices, such control can cause large errors in kinematic viscosity flow timemea
43、surements.6.7 Secondary Viscosity Standards.47. Procedure for Cleaning Viscometers and Filter Screen7.1 Apply air pressure or suction to the viscometer to remove any previous test specimen. Allow the viscometer to drain for 5min.7.1.1 Wash the viscometer four times, inside and out, with fresh toluen
44、e (WarningFlammable) using suction as required.Allow the viscometer to drain.7.1.2 Wash the viscometer four times, inside and out, with acetone, and allow to drain for 5 min. Then dry with vacuum suction.6.1.3 Clean the viscometer thoroughly by filling it completely with glass cleaning solution. All
45、ow to drain for 5 min.6.1.4 Rinse viscometer inside and out with distilled water until all traces of the cleaning solution are completely removed.Allowto drain for 5 min.6.1.5 Dry in oven at approximately 100C (212F).7.2 If organic or other deposits are visible in the viscometer, clean the viscomete
46、r thoroughly by filling it completely with glasscleaning solution for several hours to remove residual traces of organic deposits.Allow to drain for 5 min. It is essential that strongalkaline cleaning solutions are not used as changes in the viscometer calibration can occur.7.2.1 Rinse viscometer in
47、side and out with distilled water until all traces of the cleaning solution are completely removed.Allowto drain for 5 min.7.2.2 Dry with filtered dry air, a vacuum line, or in an oven at approximately 100 C for approximately 30 min until all tracesof water are removed.7.3 Clean the filter screen by
48、 first disassembling the screen (if practicable).7.3.1 Rinse thoroughly with fresh toluene (WarningFlammable).4 Viscosity standards for calibration of viscometers may be purchased at the Cannon Instrument Co., State College, PA. Calibrated viscometers are also commerciallyavailable.D2532 1437.3.2 Ri
49、nse thoroughly with fresh acetone (WarningFlammable).7.3.3 Dry in oven at approximately 100C (212F).100 C.8. Procedure8.1 For the duration of the test, maintain the bath temperature at the required temperature 60.03C (60.05F).60.03 C.8.2 Charge the clean, dry viscometer as prescribed in Test Method D445 and Specifications D446.8.2.1 Affix the drying tubes and carefully flush the moist room air from the viscometer by placing vacuum to the drying tubes.Draw the sample into the working capillary and timing bu
