1、Designation: D5984 11Standard 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 D5984; the number immediately following the designation indicates the year oforiginal adoption o
2、r, 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 a procedure for determining thebasic constituents in
3、petroleum products in the field or labora-tory using a pre-packaged test kit. The test uses a micro-titration resulting in a visual endpoint facilitated by a colorindicator.1.1.1 This test method covers base numbers from 0 to 20. Itcan be extended to higher ranges by diluting the sample or byusing a
4、 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 closely specified condi-tions with standardized reagen
5、ts, 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 to be regarded as thestandard. The values given in
6、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 and determine the applica-bility of regulatory limi
7、tations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2896 Test Method for Base Number of Petroleum Prod-ucts by Potentiometric Perchloric Acid TitrationD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic S
8、ampling of Petroleum andPetroleum Products3. Terminology3.1 Definitions:3.1.1 base number, nthe quantity of a specified acid,expressed in terms of the equivalent number of milligrams ofpotassium hydroxide per gram of sample, required to titrate asample in a specified solvent to a specified endpoint
9、using aspecified detection system.3.1.1.1 DiscussionThis test method uses fixed amounts ofisooctane and alcoholic hydrochloric acid as the sample solventand the endpoint is defined as the amount of titrant required toreach a yellow endpoint with a methyl red indicator solution.4. Summary of Test Met
10、hod4.1 To determine the base number of an oil sample, thesample is dissolved in a fixed amount of isooctane andalcoholic hydrochloric acid. The solution is mixed well with 7mL of sodium chloride solution and the aqueous and organicphases are allowed to separate. The aqueous phase is thendecanted off
11、 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. Whenthe solution changes from magenta to yellow, the titration isstopped and the base number is read off the side of the titrationburette.5.
12、Significance and Use5.1 New and used petroleum products can contain basicconstituents that are present as additives or as degradationproducts formed during service. The amount of these additivesin an oil can be determined by titrating against an acid. Thebase number is a measure of the amount of bas
13、ic 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 condemning limits must be empirically estab-lished.5.2 This test method uses reagents that are considered lesshazardous than most reagents used in a
14、lternate base numbermethods. It uses pre-packaged reagents to facilitate basenumber determinations in the field where scientific equipmentis unavailable and quick results are at a premium.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the
15、 direct responsibility of SubcommitteeD02.06 on Analysis of Lubricants.Current edition approved May 15, 2011. Published July 2011. Originallyapproved in 1996. Last previous edition approved in 2007 as D598497(2007).DOI: 10.1520/D5984-11.2For referenced ASTM standards, visit the ASTM website, www.ast
16、m.org, orcontact ASTM Customer Service 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 B
17、ox C700, West Conshohocken, PA 19428-2959, United States.NOTE 1Results obtained by this test method3are similar to thoseobtained by Test Method D2896.6. Apparatus46.1 Sampling Syringe, fixed volume of 0.35 mL.6.2 Test Tubes (2), pliable, plastic with threaded tops ca-pable of holding at least 20 mL,
18、 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 wool has beenfound to work well for this purpose.7. Rea
19、gents 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 Specification D1193.7.3 Hydrochloric Acid, 0.114 mol/L
20、(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 grade, CO2free water.7.6 Sodium Hydroxide Titrant, 1.0 mL o
21、f 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. Procedure58.1 Obtain samples for analysis by this test method in
22、accordance with instructions given in Practice D4057 orD4177.8.2 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 further.8.3 It is essential to ensure the sample is repre
23、sentative 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 used oils can change appreciably in storage, samplesshall be
24、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 sampling syringeuntil it stops. Remove the syringe from t
25、he 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 the oil with the diluent. Add 1.0 mLof 0.114 mol/L alcohol
26、ic 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 dispersed. Stand the tube upside-downon its cap and allow the a
27、queous 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 through the filter into the second test tube.Stop dispensing
28、 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 methyl red indicator solution and disperse theindicator t
29、hroughout 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 the burette barrel. The reading should be taken at the tip
30、 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 different laboratories (Research Report D02-1345) is as follows:9
31、.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 test method, exceed the following value only in one case i
32、ntwenty: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 long run, in the normal and correct operation of the testmet
33、hod, exceed the following values only in one case intwenty:R 5 1.91 base number units mgKOH/g sample! (2)9.2 BiasThis procedure has no bias because the basenumber can be defined only in terms of the test method.10. Keywords10.1 base number; color-indicator titration; lubricants; testkit3Supporting d
34、ata have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1345.4A patent 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 5,3
35、66,898, Dexsil Corp.,Hamden, CT. If you are aware of alternative, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.D5984 112SUMMARY OF CHANGESSubcommittee D02
36、.06 has identified the location of selected changes to this standard since the last issue(D598497(2007) that may impact the use of this standard.(1) Updated 3.1.1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this s
37、tandard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof 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 re
38、viewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of therespons
39、ible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your 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
40、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5984 113
