1、Designation: D 6375 09An American National StandardStandard Test Method forEvaporation Loss of Lubricating Oils by ThermogravimetricAnalyzer (TGA) Noack Method1This standard is issued under the fixed designation D 6375; the number immediately following the designation indicates the year oforiginal a
2、doption 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 procedure for determiningthe Noack evapo
3、ration loss of lubricating oils using a thermo-gravimetric analyzer test (TGA). The test method is applicableto base stocks and fully formulated lubricant oils having aNoack evaporative loss ranging from 0 to 30 mass %. Thisprocedure requires much smaller specimens, and is faster whenmultiple sample
4、s are sequentially analyzed, and safer than thestandard Noack method using Woods metal.1.2 The evaporative loss determined by this test method isthe same as that determined using the standard Noack testmethods.1.3 The values stated in SI units are to be regarded asstandard. No other units of measure
5、ment are included in thisstandard.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 limita
6、tions prior to use.2. Referenced Documents2.1 ASTM Standards:2D 5800 Test Method for Evaporation Loss of LubricatingOils by the Noack MethodD 6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD 6792 Practice fo
7、r Quality System in Petroleum Productsand Lubricants Testing LaboratoriesE 1582 Practice for Calibration of Temperature Scale forThermogravimetry3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Noack reference oilthe oil provided by Noackequipment manufacturers to check proper
8、operation of theNoack evaporation tester.3.1.2 Noack reference timethe time (in minutes) requiredfor the Noack reference oil to reach its known Noack evapo-rative loss under the conditions used in this test method.3.1.3 TGA Noack volatilitythe evaporative loss (in masspercent) of a lubricant as dete
9、rmined in this test method.4. Summary of Test Method4.1 A lubricant specimen is placed in an appropriate TGAspecimen pan. The pan is placed on the TGA pan holder andquickly heated to between 247 and 249C under a stream of air,and then held isothermal for an appropriate time. Throughoutthis process,
10、the TGA monitors and records the mass lossexperienced by the specimen due to evaporation. The Noackevaporation loss is subsequently determined from the specimenweight percent loss versus time curve (TG curve) as the masspercent lost by the specimen at the Noack reference timedetermined under the sam
11、e TGA conditions.5. Significance and Use5.1 This test method is a safe and fast alternative fordetermination of the Noack evaporation loss of a lubricant.5.2 The evaporation loss of a lubricant is important in thehot zones of equipment where evaporation of part of thelubricant may increase lubricant
12、 consumption.5.3 Some lubricant specifications cite a maximum allowableevaporative loss.6. Apparatus6.1 Thermogravimetric Analyzer, with the capability tomeet all the conditions required for this test method, along withthe software necessary to complete the required analyses.6.2 Aluminum Specimen Pa
13、nThis shall be cylindrical, andhave a minimum inside diameter/height ratio of 0.45 and avolume of 50 6 3 L. If the pans provided by the particularTGA manufacturer do not meet these criteria, alternative pansmay be used and adapted to fit the pan holder of the TGA.Examples of some of the adaptations
14、used during the evalua-tion of this test method are shown in Fig. 1.6.3 Pressure Regulator, capable of maintaining air deliverypressure at the level required by the TGA instrument.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct
15、responsibility of SubcommitteeD02.06 on Analysis of Lubricants.Current edition approved March 1, 2009. Published March 2009. Originallyapproved in 1999. Last previous edition approved in 2005 as D 637505.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Se
16、rvice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer 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 19
17、428-2959, United States.6.4 Flowmeter, with a flow control valve capable of settingand measuring the air throughput required by the TGA instru-ment.7. Reagents and Materials7.1 TGA Temperature Calibration StandardsThese mate-rials will depend on the particular TGA apparatus and itscapabilities. The
18、TGA manufacturer typically provides themand describes their use in the operating manual for theinstrument.7.2 Compressed air at a pressure suitable for operation ofthe TGA instrument. Reagent grade air is not necessary butmay be used if there are concerns over possible contaminationof the internal p
19、arts of the TGA.7.3 Noack Reference OilOil having a known Noackevaporative loss, the value of which is provided by themanufacturer.8. TGA Preparation and Calibration (see Note 1)NOTE 1This section only needs to be done if TGA has been idle foran extended period of time, has had significant repairs m
20、ade to it, or hasbeen mishandled or its location changed.8.1 Check the temperature correlation between the speci-men and control temperatures in accordance with TGA manu-facturers recommendations or Practice E 1582. Use calibra-tion standards that will bracket 250C. When necessary,recalibrate, and r
21、egenerate correlation.8.2 When necessary, burn out the TGA to remove anycondensed liquids or deposits, which may have formed on itsinside surfaces. Generally, burn out is accomplished by raisingthe temperature of the TGAto a minimum of 800C with an airpurge from 200 to 500 mL/min, and by maintaining
22、 it at thishigh temperature until no smoke is detected from the TGA gasexhaust tube. Normally 15 to 20 min at these conditions areenough to remove most deposits. (WarningDo not place aspecimen pan in the TGAduring this operation. It will melt andmay damage the balance or furnace mechanisms.)8.3 Chec
23、k operation of TGA balance and adjust whennecessary. Follow manufacturers procedure and recommenda-tions.9. Procedure9.1 Determination of Specimen Mass:9.1.1 Determine the nominal internal diameter (in centime-tres) of the specimen pans by measuring the internal diameterof 10 different pans and aver
24、aging the results.Acaliper shall beused to make this measurement.9.1.2 Calculate the specimen mass using following equa-tion:Ms5 350 ID!3(1)Ms= Specimen mass, mg (round to closest whole mg.)ID = Nominal inside diameter of specimen pan, cm (see9.1.1).9.2 Air Flowrate Set air flowrate to that recommen
25、ded bythe TGA manufacturer or higher if during the initial tests withthe Noack reference oil there appears to be condensation onany part of the TGA balance mechanism or furnace lining.Repeat 8.1 with the new flow rate.9.3 Temperature Program (see Note 2):NOTE 2This section only needs to be done duri
26、ng the initial set up ofthe method in the TGA.9.3.1 Using the correlation from 8.1, determine the finalprogram temperature required to obtain a final specimentemperature of 249C.9.3.2 Program the TGA to heat the specimen from 50C tothe final program temperature determined in 9.3.1 at heatingrate(s)
27、that will simulate the specimen heating rate of thestandard Noack methods (;100C/min to 220C and 10C/minfrom 220C to 249C). Some guidance on how to achieveacceptable heating rates can be obtained from the examplesshown in Fig. 2. Maintain the final program temperature for 30min (see Note 3).NOTE 3Th
28、e 30 min isothermal hold may be adjusted after the Noackreference oil has been tested and the Noack reference time for theinstrument has been established (see 9.4). The isothermal hold can then beset to be 2 min longer than the measured Noack reference time.9.3.3 Tare an empty specimen pan in accord
29、ance with theTGA operating manual.9.3.4 Add the required mass (6 3 mg) (as determined in9.1) of the Noack reference oil to the tared pan.9.3.5 Place the pan on the TGA pan holder, and runspecimen through the temperature program, as described in9.3.2.9.3.6 From the data obtained in 9.3.5, generate a
30、plot of timeversus specimen temperature. Determine whether at any timethe specimen temperature was above 249C. When this occurs,proceed to 9.3.8. When it does not occur, proceed to 9.3.7.9.3.7 Temperature not over 249C: Determine the Noackreference time in accordance with 9.4.6. When the Noackrefere
31、nce time is less than 7 min, return to 9.3.2 and the reduceheating rate to extend the Noack reference time beyond 7 min.FIG. 1 Examples Showing Adaptation of Alternative Sample PansD6375092Check the specimen temperature at the Noack reference time tobe sure it is between 248 and 249C. When it is low
32、er,determine how much lower than 248.5C and increase the finalprogram temperature by this amount. Go to 9.4.9.3.8 Temperature over 249C: Modify the TGA tempera-ture program to eliminate the temperature overshoot. This isgenerally accomplished by splitting the program into twostages, by reducing the
33、heating rate by the final programtemperature, or by a combination thereof. An example of howtemperature overshoot was eliminated in a particular instru-ment is shown in Fig. 3. Repeat 9.3.3-9.3.6 until an appropriatetemperature program has been obtained.9.4 Determination of Noack Reference Time:NOTE
34、 4Important: This determination shall be completed each dayprior to evaluating any test specimens.9.4.1 Set air flowrate in accordance with 9.2.9.4.2 Enter final temperature program established in 9.3.9.4.3 Tare an empty specimen pan in accordance with theTGA operating manual.9.4.4 Add the required
35、mass (as determined in 9.1)oftheNoack reference oil to the tared pan. Whether specimen isadded volumetrically or gravimetrically, the actual mass shallbe within 63 mg of the calculated specimen mass. Adjustspecimen mass to meet this requirement.9.4.5 Place the pan on the TGA pan holder, and runspeci
36、men.9.4.6 From the thermogravimetric curve generated in 9.4.5,determine the time (if possible to the closest 0.01 min) requiredfor the Noack reference oil to reach its Noack evaporative loss.This time is the Noack reference time. Record this time, as itwill be used in 9.5 to determine the TGA Noack
37、volatility ofthe test lubricants. An example of a TG curve for the Noackreference oil and how to use it to determine the Noackreference time is shown in Fig. 4 (Curve 1). The isothermalhold of the TGA temperature program can now be modified tothe Noack reference time plus 2 min. This will expedite f
38、uturedeterminations.9.4.7 Check that the specimen temperature at the Noackreference time is between 247 and 249C. When the tempera-ture is outside this range, burn out TGA in accordance with 8.2and repeat 9.4.9.4.8 Compare the measured Noack reference time to thosemeasured in prior days. When the di
39、fference is more than 10 %,check operation of the TGA in accordance with Section 8.When significant repairs or modifications, such as replacementof the balance mechanisms, temperature sensor, and so forth,have been made to the TGA since the previous time the Noackreference time was measured, the tes
40、t method shall be repeatedstarting with Section 8.9.5 Determination of TGA Noack Volatility of Test Lubri-cant:9.5.1 Using a new specimen pan, repeat 9.4.1-9.4.5 usingthe test lubricant in place of the Noack reference oil.9.5.2 Using the TG curve for the test lubricant and theNoack reference time fr
41、om 9.4.6, determine the mass loss (inmass %) of the test lubricant at the Noack reference time. Thisis the TGA Noack volatility for the test lubricant. Examples ofhow to determine the TGA Noack volatility of test lubricantsare shown in Fig. 4 (Curves 2 and 3). Check that the specimentemperature at t
42、he Noack reference time is between 247 and250C. When it is not, reinitiate the test starting with Section8.9.5.3 The TGA shall be burned out (see 8.2) on a regularbasis. An estimate of how many tests can be done on aparticular TGAbefore it needs to be burned out can be obtainedby performing consecut
43、ive tests with the Noack reference oiluntil the difference in the Noack reference time between any ofthe determinations is greater than 10 %. The number of testsbetween burn outs may be increased by operating at a higherair flowrate (see 9.2).10. Report10.1 Report the TGA Noack volatility of the tes
44、t lubricant,as determined in 9.5.2, to the closest 0.01 mass percent.FIG. 2 TGA Noack Programs and Resulting Specimen Heating RatesD637509311. Quality Control (QC)11.1 Confirm the performance of the instrument or the testprocedure by analyzing a QC sample.11.1.1 If a suitable QC oil or basestock sam
45、ple is notavailable, prepare QC sample from a stock of such material.11.1.2 When QC/Quality Assurance (QA) protocols arealready established in the testing facility, they may be usedwhen they confirm the reliability of the test result.11.1.3 When there is no QC/QA protocol established in thetesting f
46、acility, Appendix X1 can be used as the QC/QAsystem.12. Precision and Bias312.1 On the basis of an interlaboratory round robin consist-ing of nine laboratories testing eight oils with TGAinstrumentsfrom five different manufacturers, the following precision andbias were determined for this procedure.
47、12.2 Repeatability Two determinations made on the samesample within a short interval of time, by the same operatorusing the same TGA equipment, in the normal and correctoperation of this test method, should differ by more than thefollowing value only in one case in twenty.Repeatability 5 0.31 TGA No
48、ack Volatility!0.60(2)12.3 Reproducibility Two determinations made on thesame sample by different operators or using different TGAequipment, in the normal and correct operation of this testmethod, should differ by more than the following value only inone case in twenty.Reproducibility 5 0.39 TGA Noa
49、ck Volatility!0.60(3)12.4 BiasWithin the repeatability of this test method, nosignificant bias was found between the Noack volatility deter-mined by this test method and those determined using TestMethod D 5800.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1447.FIG. 3 TGA Noack Programs and Resulting Specimen Heating Rates Showing Modification of TGA Program to Eliminate Overshoot inSpecimen TemperatureFIG. 4 Determination of Noack Reference Time and Test Oils Evaporat
