1、Designation: D 5984 97 (Reapproved 2007)An American National StandardStandard Test Method forSemi-Quantitative Field Test Method for Base Number inNew and Used Lubricants by Color-Indicator Titration1This standard is issued under the fixed designation D 5984; the number immediately following the des
2、ignation indicates the year oforiginal 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.1. Scope1.1 This test method covers a pr
3、ocedure for determining thebasic constituents in petroleum products in the field or labora-tory using a pre-packaged test kit. The test uses a micro-titration resulting in a visual end point facilitated by a colorindicator.1.1.1 This test method covers base numbers from 0 to 20. Itcan be extended to
4、 higher ranges by diluting the sample or byusing a smaller sample size; however, the precision data wereobtained for base numbers up to 20.1.2 This test method can be used to indicate relative changesthat occur in an oil during use under oxidizing conditions.Although the test is performed under clos
5、ely specified condi-tions with standardized reagents, the test method does notmeasure an absolute basic property that can be used to predictperformance of an oil under service conditions. No generalrelationship between bearing corrosion and base number isknown.1.3 The values stated in SI units are t
6、o be regarded as thestandard. The values given in parentheses are for informationonly.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 a
7、nd determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 2896 Test Method for Base Number of Petroleum Prod-ucts by Potentiometric Perchloric Acid TitrationD 4057 Practice for Manual Sampling of Petroleu
8、m andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4739 Test Method for Base Number Determination byPotentiometric Titration3. Terminology3.1 Definitions:3.1.1 base number, nthe quantity of an acid, expressed interms of the equivalent number of milligra
9、ms of potassiumhydroxide per gram of sample, that is required to titrate asample dissolved in the specified solvent to a specified endpoint (for example, Test Method D 4739).3.1.2 DiscussionThis test method uses fixed amounts ofisooctane and alcoholic hydrochloric acid as the sample solventand the e
10、nd point is defined as the amount of titrant required toreach a yellow end-point with a methyl red indicator solution.4. Summary of Test Method4.1 To determine the base number of an oil sample, thesample is dissolved in a fixed amount of isooctane andalcoholic hydrochloric acid. The solution is mixe
11、d well with 7mL of sodium chloride solution and the aqueous and organicphases are allowed to separate. The aqueous phase is thendecanted off and a small amount of methyl red indicator isadded. The solution is titrated with a solution of sodiumhydroxide contained in a calibrated 1 mL micro-burette. W
12、henthe solution changes from magenta to yellow, the titration isstopped and the base number is read off the side of the titrationburette.5. Significance and Use5.1 New and used petroleum products can contain basicconstituents that are present as additives or as degradationproducts formed during serv
13、ice. The amount of these additivesin an oil can be determined by titrating against an acid. Thebase number is a measure of the amount of basic substance inthe oil, always under the conditions of the test. A decrease inbase number is often used as a measure of lubricant degrada-tion, but any condemni
14、ng limits must be empirically estab-lished.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.06 on Analysis of Lubricants.Current edition approved May 1, 2007. Published June 2007. Originallyappro
15、ved in 1996. Last previous edition approved in 2002 as D 5984 97 (2002).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 to the standards Document Summary page onthe AS
16、TM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 This test method uses reagents that are considered lesshazardous than most reagents used in alternate base numbermethods. It uses pre-packaged reagents to facilitate base
17、number determinations in the field where scientific equipmentis unavailable and quick results are at a premium.NOTE 1Results obtained by this test method3are similar to thoseobtained by Test Method D 2896.6. Apparatus46.1 Sampling Syringe, fixed volume of 0.35 mL.6.2 Test Tubes (2), pliable, plastic
18、 with threaded tops ca-pable of holding at least 20 mL, one with a standard screw capand the second with a screw cap that is equipped with adispenser nozzle.6.3 Titrating Burette, disposable, 1.0 mL.6.4 Filter Funnel, capable of removing suspended oil drop-lets from aqueous solutions. Polypropylene
19、wool has beenfound to work well for this purpose.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Pre-packaged, manufactured test kits shall useonly reagent grade chemicals.7.2 Purity of WaterAll water will be reagent water asspecified by Type III of
20、Specification D 1193.7.3 Hydrochloric Acid, 0.114 mol/L (60.001 mol/L) HCl inpropan-2-ol (isopropyl alcohol). (WarningFlammable.)7.4 Methyl Red Indicator, 0.05 % (m/v) solution of methylred in anhydrous ethanol. (WarningFlammable.)7.5 Sodium Chloride Solution, 7.0 mL of 20 % (m/m) NaClin reagent gra
21、de, CO2free water.7.6 Sodium Hydroxide Titrant, 1.0 mL of 0.0645 mol/L(60.0005 mol/L) NaOH sealed from the environment in aplastic titration burette which is indexed with base numberunits from 0 to 20. (WarningToxic and corrosive.)7.7 2,2,4-Trimethyl Pentane (isooctane)(WarningFlammable.)8. Procedur
22、e58.1 Obtain samples for analysis by this test method inaccordance with instructions given in Practice D 4057 orD 4177.8.2 If a sample is to be taken directly from a hot engine,follow the manufacturers instructions for obtaining a repre-sentative sample. Allow the oil to cool to 50C beforeproceeding
23、 further.8.3 It is essential to ensure the sample is representative sinceany sediment can be acidic or basic or have adsorbed acidic orbasic material from the sample. When necessary, samples arewarmed to aid mixing. Used oils should be vigorously mixed toensure homogeneity before sampling.8.4 As use
24、d oils can change appreciably in storage, samplesshall be tested as soon as possible after removal from thelubricating system.8.5 Prepare the oil sample by shaking well to disperse anyparticulates.8.6 Place the tip of the fixed volume sampling syringe intothe oil sample. Draw back the plunger of the
25、 sampling syringeuntil it stops. Remove the syringe from the oil sample and wipethe outside clean of any excess oil. Dispense the entire volumeof the syringe into the first test tube. Replace the cap on the testtube.8.7 Add 1.0 mL of 2,2,4-trimethyl pentane (isooctane) andshake the tube well to mix
26、the oil with the diluent. Add 1.0 mLof 0.114 mol/L alcoholic HCl and shake the tube well for 30 s,allowing the acid to react with the diluted oil sample.8.8 Pour 7.0 mL 20 % NaCl solution into the oil mixture.Cap the tube and shake the mixture well for 30 s so that the twophases are completely dispe
27、rsed. Stand the tube upside-downon its cap and allow the aqueous and organic phases toseparate.8.9 Place the plastic filter into the top of the second testtube. Keeping the first test tube upside-down and vertical, openthe dispenser cap on the tube and dispense exactly 5 mL of theaqueous solution th
28、rough the filter into the second test tube.Stop dispensing as soon as 5 mL has been placed in the tube.8.10 Place the 1.0 mL micro-burette into the tube containingthe 5.0 mL of aqueous extract. Seal the burette into place byscrewing the threaded cap of the burette onto the test tube.Add0.5 mL of the
29、 methyl red indicator solution and disperse theindicator throughout the solution by gently shaking. Startslowly dispensing the titrant into the solution and shake gently.As soon as the solution turns from magenta to yellow, stop thetitration and read the result, in base number units, off the sideof
30、the burette barrel. The reading should be taken at the tip ofthe plunger.9. Precision and Bias9.1 The precision of this test method as determined by thestatistical examination of test results from 11 samples of newand used oils, covering base numbers between 0 and 20, run induplicate by nine differe
31、nt laboratories (Research Report D02-1345) is as follows:9.1.1 RepeatabilityThe difference between successive re-sults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialwould, in the long run, in the normal and correct operation ofthe
32、test method, exceed the following value only in one case intwenty:r 5 0.94 base number units mg KOH/g sample! (1)9.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, inthe lo
33、ng run, in the normal and correct operation of the testmethod, exceed the following values only in one case intwenty:R 5 1.91 base number units mgKOH/g sample! (2)3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D021345.4A paten
34、t pending field test kit containing appropriate apparatus reagents, andmaterials is available from Dexsil Corp., Hamden, CT.5This procedure is covered by U.S. patent number 5,366,898, Dexsil Corp.,Hamden, CT. If you are aware of alternative, please provide this information toASTM International Headq
35、uarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee1, which you may attend.D 5984 97 (2007)29.2 BiasThis procedure has no bias because the basenumber can be defined only in terms of the test method.10. Keywords10.1 base number; color-indicat
36、or titration; lubricants; testkitASTM 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
37、 infringement 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 s
38、tandard 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 you
39、r views 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).D 5984 97 (2007)3
