1、Designation: D 2532 03An American National StandardStandard Test Method forViscosity and Viscosity Change After Standing at LowTemperature of Aircraft Turbine Lubricants1This standard is issued under the fixed designation D 2532; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department
3、of Defense.1. Scope*1.1 This test method covers the determination of the kine-matic viscosity of aircraft turbine lubricants at low tempera-ture, and the percent change of viscosity after a 3-h and a 72-hstanding period at low temperature.1.2 This test method uses the millimetre squared per second(m
4、m2/s) as the unit of kinematic viscosity. For information, theequivalent cgs unit, the centistokes, is shown in parentheses.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all o
5、f 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. For specific hazardstatements, see Section 6.2. Referenced Docume
6、nts2.1 ASTM Standards:2D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (the Calculation of Dynamic Viscos-ity)E1 Specification for ASTM Thermometers3. Summary of Test Method3.1 Kinematic viscosity is measured at low temperature inaccordance with Test Method D 445 and at ti
7、me intervals of 3 hand 72 h.NOTE 1This test method was developed and the precision establishedon tests at 53.9C (65F). It is also applied at 40C (40F) and maybe used at other temperatures. Viscosities may be measured and reportedat other intervals as agreed by the contracting parties.4. Significance
8、 and Use4.1 Aircraft turbine lubricants, upon standing at low tem-peratures for prolonged periods of time, may show an increasein kinematic viscosity. This increase may cause lubricationproblems in aircraft engines. Thus, this test method is used toensure that the kinematic viscosity does not exceed
9、 themaximum kinematic viscosity in certain specifications foraircraft turbine lubricants.5. Apparatus5.1 Viscometers, drying tubes, low-temperature bath, ther-mometer, timer, secondary viscosity standard, filter, and clean-ing supplies are described in detail in Test Method D 445.5.2 ViscometerThe v
10、iscometer shall meet the require-ments of Test Method D 445 and be of the type in which thesample can be rerun without cleaning the viscometer. Suitableholders should be used. For convenience it is recommendedthat the viscometer size be chosen to keep the efflux timebetween 200 and 1000 s.5.3 Drying
11、 TubesFit the viscometer openings with dryingtubes filled with indicating silica gel, using cotton at top andbottom to hold the loosely packed desiccant in place. Providea cross-connection on the viscometer side of the drying tubes(which can be closed by a pinch clamp or stopcock while liquidis bein
12、g drawn into the efflux bulb) so that the restriction to airflow will not cause error. Replace the silica gel when alavender color is noticeable.5.4 Viscosity Temperature BathThe constant-temperaturebath must be capable of holding several viscometers at once. Itmust have adequate stirring of the liq
13、uid medium (Note 2) andbalance between heat losses such that the bath temperature canbe maintained at the required temperature 60.03C (60.05F).NOTE 2Isopropanol or other clear, low-freezing liquid may be used asa bath liquid.5.5 Low-Temperature Storage CabinetIf it is desired toexercise the option d
14、escribed in Note 3 (7.4), a low-temperature storage cabinet or bath shall be provided which is1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved Dec.
15、1, 2003. Published January 2004. Originallyapproved in 1966. Last previous edition approved in 1998 as D 253293 (1998).2For 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
16、to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.capable of holding the required temperature with a variationn
17、ot to exceed 60.3C (60.5F).5.6 Bath ThermometerCalibrated ASTM Kinematic Vis-cosity Test Thermometer such as 73F or 74F conforming to therequirements as prescribed in Specification E1. Other cali-brated thermometric devices are permissible provided theiraccuracy, precision, and sensitivity are equal
18、 to or better thanthe above thermometers.5.7 Secondary Viscosity Standards.36. Procedure for Cleaning Viscometers and Filter Screen6.1 Apply air pressure or suction to the viscometer toremove any previous test specimen. Allow the viscometer todrain for 5 min.6.1.1 Wash the viscometer four times, ins
19、ide and out, withfresh toluene (WarningFlammable) using suction as re-quired. Allow the viscometer to drain.6.1.2 Wash the viscometer four times, inside and out, withacetone, and allow to drain for 5 min. Then dry with suction.6.1.3 Clean the viscometer thoroughly by filling it com-pletely with glas
20、s cleaning solution. Allow to drain for 5 min.6.1.4 Rinse viscometer inside and out with distilled wateruntil all traces of the cleaning solution are completely re-moved. Allow to drain for 5 min.6.1.5 Dry in oven at approximately 100C (212F).6.2 Clean the filter screen by first disassembling the sc
21、reen(if practicable).6.2.1 Rinse thoroughly with fresh toluene (WarningFlammable).6.2.2 Rinse thoroughly with fresh acetone (WarningFlammable).6.2.3 Dry in oven at approximately 100C (212F).7. Procedure7.1 For the duration of the test, maintain the bath tempera-ture at the required temperature 60.03
22、C (60.05F).7.2 Charge the clean, dry viscometer as prescribed in TestMethod D 445.7.2.1 Affix the drying tubes and carefully flush the moistroom air from the viscometer by placing vacuum to the dryingtubes. Draw the sample into the working capillary and timingbulb so as to preclude the possibility o
23、f any traces of residuemoisture condensing on the walls of the capillary and timingbulb while the sample cools to test temperature. Moisture mustnot be allowed to condense on the walls of the workingcapillary and efflux bulb.7.2.2 Place the viscometer in the constant-temperature bath,and vertically
24、align the viscometer if a self-aligning holder hasnot been used.7.2.3 Make the first determination of kinematic viscosity 356 1 min after the viscometer is placed in the bath. Measure theefflux time as specified in Test Method D 445. Be careful thatthe stopcock or pinch clamp joining each arm of the
25、 viscometerhas been opened to ensure that there is no effect of the dryingtubes on the efflux time.7.3 Measure the kinematic viscosity after standing3hattherequired temperature. Without removal of the viscometer fromthe constant-temperature bath, repeat the viscosity determina-tion (7.2.3)at3h6 5 mi
26、n after the completion of the initialviscosity determination.7.4 Measure the kinematic viscosity after standing 72 h atthe required temperature. Without removal of the viscometerfrom the constant-temperature bath (Note 3), repeat the viscos-ity determination (7.2.3)at72h6 5 min after the completiono
27、f the initial viscosity measurement (Note 1).NOTE 3If for some reason, such as unavailability of operator atten-tion, it becomes difficult or impractical to maintain the temperature of thebath within the specified 60.03C (60.05F) variations for the entire timerequired for completion of the 72-h test
28、, the bath may be put on automaticcontrol capable of holding the required temperature at 60.3C (60.5F).Optionally, the viscometer may be removed from the bath and placed inthe low-temperature storage cabinet or bath described in 5.5. In eithercase, the viscometer shall be returned to conditions of 0
29、.03C (60.05F)and held there for at least 35 min before the viscosity is to be measuredagain.8. Calculation8.1 Calculate the kinematic viscosity as follows:Kinematic viscosity, mm2/scSt!5Ct (1)where:C = calibration constant of the viscometer at the requiredtemperature, cSt/s, andt = efflux time, s.8.
30、2 Report the viscosity in centistokes at 35 min, 3 h, and 72h.8.3 Calculate the percent viscosity change as follows:Viscosity change, percent 5 100B 2 A!/A,or 100C 2 A!/A (2)whereA = viscosity at 35 min,B = viscosity at 3 h, andC = viscosity at 72 h.9. Precision and Bias9.1 PrecisionThe following cr
31、iteria should be used forjudging the acceptability of results at a 95 % confidence level.9.1.1 RepeatabilityThe difference between successive testresults obtained by the same apparatus under constant operat-ing conditions on identical test material would, in the long run,in the normal and correct op
32、eration of this test method exceed,after the 35-min period, the values shown on the repeatabilitycurve in Fig. 1 only in one case in twenty. Differences greaterthan this should be considered suspect.9.1.2 ReproducibilityThe difference between two singleand independent test results, obtained by diffe
33、rent operatorsworking in different laboratories on identical test materialwould, in the long run, in the normal and correct operation ofthis test method exceed, after the 35-min period, the valuesshown on the reproducibility curve in Fig. 1 only in one casein twenty. Differences greater than this sh
34、ould be consideredsuspect.3Viscosity standards for calibration of viscometers may be purchased at theCannon Instrument Co., State College, PA. Calibrated viscometers are alsocommercially available.D25320329.1.3 The precision of kinematic viscosity determinationsafter standing times in excess of 35 m
35、in has not been calculatedbecause it has been found that certain oils, while held instorage at 53.9C (65F), develop characteristics that causewide variations in observed kinematic viscosities.9.2 BiasSince there is no accepted reference materialsuitable for determining the bias for this test method,
36、 nostatement on bias is being made.10. Keywords10.1 aircraft turbine lubricants; kinematic viscosity;viscositySUMMARY OF CHANGESSubcommittee D02.07 has identified the location of selected changes to this standard since the last issue(D 235293 (1998) that may the use of this standard.(1) Corrected th
37、e units on the axes of Fig. 1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof in
38、fringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this stan
39、dard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your v
40、iews known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 1 Repeatability and ReproducibilityD2532033
