1、Designation:D112111(Reapproved 2020)Standard Test Method forReserve Alkalinity of Engine Coolants and Antirusts1This standard is issued under the fixed designation D1121;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of las
2、t revision.A number 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
3、 of the reservealkalinity of new,unused engine coolants,and liquid antirustsas received,of used or unused aqueous dilutions of theconcentrated materials,and of aqueous dilutions of solidantirusts.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are includ
4、ed in thisstandard.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitation
5、s prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization Techni
6、calBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1123 Test Methods for Water in Engine Coolant Concen-trate by the Karl Fischer Reagent MethodD1176 Practice for Sampling and Preparing Aqueous Solu-tions of Engine Coolants orAntirusts for Testing PurposesD1287 Test Method
7、 for pH of Engine Coolants andAntirusts3.Terminology3.1 Definitions:3.1.1 reserve alkalinity,na term applied to engine coolantconcentrates and antirusts to indicate the amount of alkalineinhibitors present in the product.4.Summary of Test Method4.1 A 10 mL sample of concentrated coolant,antirust,coo
8、lant additive,or an aqueous engine coolant containing theseproducts,is diluted to about 100 mL with water and titratedpotentiometrically with 0.100 N hydrochloric acid to a pH of5.5.The volume of acid used is reported to the nearest 0.1 mL.The concentration of coolant or additive in the coolant solu
9、tionshall be recorded if required,for calculation of depletion of thereserve alkalinity during performance tests.5.Significance and Use5.1 Reserve alkalinity is the number of millilitres,to thenearest 0.1 mL of 0.100 N hydrochloric acid(HCl)required forthe titration to a pH of 5.5 of a 10 mL sample
10、of an undiluted,unused coolant,antirust,or coolant additive,and unused orused solutions thereof.5.2 Reserve alkalinity is a term applied to engine coolantsand antirusts to indicate the amount of alkaline componentspresent in the product.It is frequently used for quality controlduring production,and
11、values are often listed in specifications.When applied to used solutions,reserve alkalinity gives anapproximate indication of the amount of remaining alkalinecomponents.Unfortunately,the term is sometimes misused inthat its numerical value is said to be directly related to coolantquality,the higher
12、the number,the better the coolant.ASTMCommittee D15 on Engine Coolants believes there is a need tocorrect some misconceptions and place the term in its properperspective.5.3 Reserve alkalinity(R.A.)as defined in Section 3 of thismethod is the number of millilitres of 0.1 N hydrochloric acidrequired
13、to titrate 10 mLof concentrated coolant to a pH of 5.5.The term is not a completely accurate description of theproperty being measured because“alkalinity”usually refers tothe pH range above 7.0.5.4 A review of the origin of the term may be helpful inattempting to understand its proper use.When ethyl
14、ene glycolwas first used as an engine coolant,it was uninhibited.Theneed for inhibition soon became apparent and triethanolamine1This test method is under the jurisdiction of ASTM Committee D15 on EngineCoolants and Related Fluids and is the direct responsibility of SubcommitteeD15.04 on Chemical Pr
15、operties.Current edition approved Jan.1,2020.Published January 2020.Originallyapproved in 1950.Last previous edition approved in 2011 as D112111.DOI:10.1520/D112111R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Boo
16、k of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers
