1、Designation:D153495(Reapproved 2017)Standard Test Method forApproximate Acidity in Electrical Insulating Liquids byColor-Indicator Titration1This standard is issued under the fixed designation D1534;the number immediately following the designation indicates the year oforiginal adoption or,in the cas
2、e 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.Scope1.1 This test method describes the determination of theapproximate total acid value of used electrica
3、l insulatingliquids having viscosities less than 24 cSt at 40C.It is a simpleprocedure that can be applied in the field.Where a quantitativeneutralization value is required,use Test Method D664 or TestMethod D974.These test methods should be applied in thelaboratory.1.2 The values stated in SI units
4、 are to be regarded asstandard.No other units of measurement are included 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 and health practices
5、and determine the applica-bility of regulatory limitations 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
6、-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D664 Test Method for Acid Number of Petroleum Productsby Potentiometric TitrationD974 Test Method for Acid and Base Number by Color-Indicator TitrationD1193 Specifica
7、tion for Reagent Water3.Summary of Test Method3.1 To determine whether the acidity is greater or less thana specified arbitrary value,a fixed volume of liquid to be testedis added to a graduated cylinder,together with a small amountof indicator(phenolphthalein)and the appropriate quantity ofstandard
8、 potassium hydroxide solution.The mixture is shakenand allowed to separate.The color of the aqueous layer at thebottom of the container when testing mineral oils,or at the topwhen testing askarels,determines whether the acidity is lessthan or greater than the arbitrary value chosen.3.2 To determine
9、the approximate total acidity,the proce-dure is the same as described in 3.1 except that the potassiumhydroxide solution is added in small increments until the colorof the aqueous layer,after shaking and settling,is a faint pink.The volume of standard potassium hydroxide solution useddetermines the
10、approximate total acid value.4.Significance and Use4.1 The approximate acidity of used electrical insulatingoils is an estimate of the total acid value of the oil.As acidvalues increase,oil quality decreases.This is usually due tooxidation of the oil while in service.In general,acidicby-products pro
11、duce increased dielectric loss,increasedcorrosivity,and may cause thermal difficulties attributable toinsoluble components called“sludge.”This test method isadapted to a specific volume of oil;total acid values of 0.05 to0.5 mg of potassium hydroxide per gram of oil is a range whichis functionally s
12、ignificant.5.Apparatus5.1 Graduated Cylinder,50 mL,stoppered.5.2 Medicine Dropper,calibrated at 1-mL intervals.5.3 Calibrated Pipet,1-mL capacity,calibrated to deliver0.05-mL increments.6.Reagents and Materials6.1 Purity of ReagentsUse reagent grade chemicals in alltests.Unless otherwise indicated,i
13、t is intended that all reagentsshall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,where1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mitte
14、e D27.06 on Chemical Test.Current edition approved June 1,2017.Published June 2017.Originallyapproved in 1958.Last previous edition approved in 2008 as D1534 95(2008).DOI:10.1520/D1534-95R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at service
15、astm.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 intern
16、ationally 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.1 such specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indica
