1、Designation:D128711(Reapproved 2020)Standard Test Method forpH of Engine Coolants and Antirusts1This standard is issued under the fixed designation D1287;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A num
2、ber 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.Scope1.1 This test method covers the determination of the pH ofunu
3、sed engine coolants and antirusts,and used or unusedaqueous dilutions of the concentrated products.NOTE1Antirusts in solid form are not included in this test method.NOTE2It is believed that this procedure gives all the informationrequired for determining the pH of samples of engine coolant or antiru
4、stlikely to be encountered.Should additional information on pH determi-nations be needed,reference should be made to Test Method E70.1.2 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 establis
5、h appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for t
6、heDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1176 Practice for Sampling and Preparing Aqueous Solu-tions of Engine Coolants orAntirusts for Testing Purpo
7、sesE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3.Summary of Test Method3.1 A sample,as received or after dilution with a specifiedvolume of distilled water,is placed in a beaker or sample cupand the pH measured with a pH meter and combinationelectrode or associated glass-satur
8、ated calomel electrode pair.NOTE3The readings of the meter in the case of the concentratedproducts are not pH values according to the accepted definition,but areapparent pH values which are useful in the interpretation of the conditionof the product.4.Significance and Use4.1 pH is a measure of the h
9、ydrogen ion concentration andindicates whether an engine coolant,antirust,or a solution ofthese compounds is acidic,alkaline,or neutral.4.2 The pH range includes values from 0 to 14.Values from0 to 7 represent the acidic half of the scale.Values from 7 to 14represent the alkaline or basic half of th
10、e scale.The pH value7 is considered neutral,as it is neither acidic nor alkaline.4.3 pH is sometimes used for production quality control.Itis generally desirable that engine coolants have an alkaline pH.4.4 pH is not significant from the standpoint of predictingservice life.The pH of used engine coo
11、lants or antirustsolutions is not a dependable indication of either existingeffectiveness or remaining life of the solution.5.Apparatus5.1 The pH meter,glass electrode,and calomel electrode,shall be as specified in the Annex.NOTE4In pH operation,the meter may be set up to perform one-,two-,or up to
12、five-point standardizations or may be set up to automaticallyrecognize U.S.standard(pH 4,7 and 10)buffers,NIST/International(pH1.68,4.01,6.86,9.18 and 12.46)buffers,or a custom user-centered set ofbuffers,or both.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unles
13、s otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is of1This test metho
14、d is under the jurisdiction of ASTM Committee D15 on EngineCoolants and Related Fluids and is the direct responsibility of SubcommitteeD15.04 on Chemical Properties.Current edition approved Jan.1,2020.Published January 2020.Originallyapproved in 1953 as D128753 T.Last previous edition approved in 20
15、11 asD128711.DOI:10.1520/D128711R20.2For 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 ASTM website.3Reagent Chemicals,American Ch
16、emical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance
