1、Designation:D112322Standard Test Methods forWater in Engine Coolant Concentrate by the Karl FischerReagent Method1This standard is issued under the fixed designation D1123;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of l
2、ast 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 These test methods cover the determinat
3、ion of the waterpresent in new or unused glycol-based coolant concentratesusing a manual(Test Method A)or an automatic(Test MethodB)coulometric titrator procedure.1.2 Many carbonyl compounds react slowly with the Fis-cher reagent,causing a fading end point and leading to highresults.A modified Fisch
4、er reagent procedure is included thatminimizes these undesirable and interfering reactions.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety problems,if any,associa
5、ted 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 limitations prior to use.For specific hazards statements see Sections 8 and 16.1.5 This international standard was
6、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 TechnicalBarriers to Trade(TBT)Committee.2.Referenced Doc
7、uments2.1 ASTM Standards:2D156 Test Method for Saybolt Color of Petroleum Products(Saybolt Chromometer Method)D1176 Practice for Sampling and Preparing Aqueous Solu-tions of Engine Coolants orAntirusts for Testing PurposesD1193 Specification for Reagent WaterE203 Test Method for Water Using Volumetr
8、ic Karl FischerTitration3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 color end pointthat point during the titration whenthe color change from yellow to orange-red is sharp and easilyrepeated.The orange-red color must persist for at least 30 s inorder to indicate an end point
9、.3.1.1.1 DiscussionView the color by transmitted daylightor by transmitted light from an artificial daylight lamp,such asone that complies with the specification given in Test MethodD156.3.1.2 instrument end pointfor the purpose of these tests,that point in the titration when two small platinum elec
10、trodes,upon which a potential of 20 mV to 50 mV has been impressed,are depolarized by the addition of 0.05 mL of Fischer reagent(6 mg of water/mL),causing a change of current flow of 10 Ato 20 A that persists for at least 30 s.3.1.2.1 DiscussionThis end point is sometimes incorrectlycalled the“dead
11、stop,”which is the reverse of the above.4.Summary of Test Method4.1 These test methods are based essentially on the reduc-tion of iodine by sulfur dioxide in the presence of water.Thisreaction can be used quantitatively only when pyridine and analcohol are present to react as follows:I21SO21H2OSO312
12、HI(1)4.2 In order to determine water,Karl Fischer reagent isadded to a solution of the sample in anhydrous high-puritymethanol until all water present has been consumed.This isevidenced by the persistence of the orange-red end point color,or alternatively by an indication on a galvanometer or simila
13、rcurrent-indicating device that records the depolarization of apair of noble metal electrodes.The reagent is standardized bythe titration of water.1These test methods are under the jurisdiction of ASTM Committee D15 onEngine Coolants and Related Fluids and are the direct responsibility of Subcom-mit
14、tee D15.04 on Chemical Properties.Current edition approved March 1,2022.Published April 2022.Originallyapproved in 1950.Last previous edition approved in 2015 as D1123 99(2015).DOI:10.1520/D1123-22.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at
15、serviceastm.org.For Annual Book 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
16、 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 to Trade(TBT)Committee.1NOTE1It is believed that these methods give all the informationrequired for determining the water in coolant formulations.Shouldadditional information on water determinations be needed,referenceshould be made to Test Method E203.5.Significance a