ASTM_D_6423_-_20a.pdf

Designation:D642320aStandard Test Method forDetermination of pHe of Denatured Fuel Ethanol andEthanol Fuel Blends1This standard is issued under the fixed designation D6423;the number immediately following the designation 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()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers a procedure to determine ameasure of the hydrogen ion activity of high ethanol contentfuels.These include denatured fuel ethanol and ethanol fuelblends.The test method is applicable to denatured fuel ethanoland ethanol fuel blends containing ethanol at 51%by volume,or more.1.2 Hydrogen ion activity as measured in this test method isdefined as pHe.A pHe value for alcohol solutions is notcomparable to pH values of water solutions.1.2.1 The value of pHe measured will depend somewhat onthe fuel blend,the stirring rate,and the time the electrode is inthe fuel.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 Hydrogen ion activity in water is expressed as pH andhydrogen ion activity in ethanol is expressed as pHe.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 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 TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4175 Terminology Relating to Petroleum Products,LiquidFuels,and LubricantsD4806 Specification for Denatured Fuel Ethanol for Blend-ing with Gasolines for Use as Automotive Spark-IgnitionEngine FuelD4814 Specification for Automotive Spark-Ignition EngineFuelD5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines3.Terminology3.1 For general terminology,refer to Terminology D4175.3.2 Definitions:3.2.1 conventional-fuel vehicle,na vehicle designed tooperate on spark-ignition engine fuel that complies withSpecification D4814.D57983.2.2 denaturants,nmaterials added to ethanol to make itunsuitable for beverage use under a formula approved by aregulatory agency to prevent the imposition of beveragealcohol tax.D48063.2.2.1 DiscussionDenaturants are only those materialsadded by the denaturer to comply with the approved formula;any materials absorbed later are not denaturants.3.2.3 denatured fuel ethanol,nfuel ethanol made unfit forbeverage use by the addition of denaturants under formula(s)approved by the applicable regulatory agency to prevent theimposition of beverage alcohol tax.D48063.2.4 ethanol,nethyl alcohol,the chemical compound,CH3CH2OH.D48063.2.5 ethanol fuel blend,nan automotive spark-ignitionengine fuel composed of hydrocarbon and ethanol blendstocksfor flexible-fuel vehicles with ethanol concentrations greaterthan those used for conventional-fuel vehicles.D57983.2.5.1 DiscussionEthanol fuel blends are often referredto as Ethanol Flex Fuel or EXX,where XX represents thenominal percentage by volume of denatured fuel ethanol in thefinished fuel.D57983.2.6 flexible-fuel vehicle,na vehicle designed to operateon both gasoline or ethanol fuel blends and can operate on anymixture of both.D57981This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.A0.02 on Oxygenated Fuels and Components.Current edition approved July 1,2020.Published July 2020.Originally approvedin 1999.Last previous edition approved in 2020 as D6423 20.DOI:10.1520/D6423-20A.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.*A Summary of Changes section appears at the end of this standardCopyright 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 to Trade(TBT)Committee.3.2.6.1 DiscussionIn the United States,these vehicleshave U.S.EPA emissions certifications using gasoline comply-ing with U.S.EPA requirements and ethanol fuel blen