ASTM_D_3635_-_13_2021.pdf

Designation:D363513(Reapproved 2021)Standard Test Method forDissolved Copper In Electrical Insulating Oil By AtomicAbsorption Spectrophotometry1This standard is issued under the fixed designation D3635;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.Scope1.1 This test method covers the determination of copper innew or used electrical insulating oil of petroleum origin byatomic absorption spectrophotometry.1.2 The lowest limit of detectability is primarily dependentupon the method of atomization,but also upon the energysource,the fuel and oxidant,and the degree of electricalexpansion of the output signal.The lowest detectable concen-tration is usually considered to be equal to twice the maximumvariation of the background.For flame atomization,the lowerlimit of detectability is generally in the order of 0.1 ppm or 0.1mg/kg.For non-flame atomization,the lower limit of detect-ability is less than 0.01 ppm.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 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 WaterD3487 Specification for Mineral Insulating Oil Used inElectrical ApparatusD5222 Specification for High Fire-Point Mineral ElectricalInsulating Oils3.Summary of Test Method3.1 The test specimen of oil is filtered and diluted with anappropriate organic solvent and analyzed in an atomic absorp-tion spectrophotometer.Alternate procedures are provided forinstruments employing flame and non-flame atomization.Con-centration is determined by means of calibration curves pre-pared from standard samples.4.Significance and Use4.1 Electrical insulating oil may contain small amounts ofdissolved metals derived either directly from the base oil orfrom contact with metals during refining or service.Whencopper is present,it acts as a catalyst in promoting oxidation ofthe oil.This test method is useful for research for new oils andto assess the condition of service-aged oils.Considerationshould be given to the limits of detection outlined in the scope.5.Apparatus5.1 Volumetric flasks,100-mL capacity.5.2 Membrane filter,0.45 m.5.3 Burets,5-mL and 50-mL capacity.5.4 Atomic Absorption Spectrophotometer The instrumentshall have an atomizer,a spectral energy source,usuallyconsisting of a copper hollow cathode lamp,a monochromatorcapable of isolating the desired line of radiation,an adjustableslit,a photomultiplier tube or other photosensitive device as alight measuring and amplifying device,and a read-out mecha-nism for indicating the amount of absorbed radiation.WarningProper ventilation must be provided to removetoxic metal vapors.5.4.1 Instruments employing flame atomization require anebulizer assembly,burner head,and suitable pressure andflow regulating devices to maintain constant oxidant and fuelflow for the duration of the tests.5.4.1.1 Glass Syringe,10-mL capacity.1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee D27.03 on Analytical Tests.Current edition approved Dec.1,2021.Published January 2022.Originallyapproved in 1977.Last previous edition approved in 2013 as D3635 13.DOI:10.1520/D3635-13R21.2For 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.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 to Trade(TBT)Committee.1?5.4.2 Instruments employing non-flame atomization requirea suitable pressure regulating device to maintain an inertatmosphere.5.4.2.1 Graphite Furnace with background correction.5.4.2.2 Output Device,Printer or Strip Chart Recorder(ifper