ASTM_D_7843_-_21.pdf

Designation:D784321Standard Test Method forMeasurement of Lubricant Generated Insoluble ColorBodies in In-Service Turbine Oils using Membrane PatchColorimetry1This standard is issued under the fixed designation D7843;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 extracts insoluble contaminants from asample of in-service turbine oil onto a patch and the color ofthe membrane patch is analyzed by a spectrophotometer.Theresults are reported as a E value,within the CIELAB scale.1.2 This test method is not appropriate for turbine oils withdyes.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:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4378 Practice for In-Service Monitoring of Mineral Tur-bine Oils for Steam,Gas,and Combined Cycle TurbinesD4898 Test Method for Insoluble Contamination of Hydrau-lic Fluids by Gravimetric AnalysisD5452 Test Method for Particulate Contamination in Avia-tion Fuels by Laboratory FiltrationD7317 Test Method for Coagulated Pentane Insolubles inUsed Lubricating Oils by Paper Filtration(LMOAMethod)E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 CIELAB color scales,nCIE 1976 L*,a*,b*opponent-color scales,in which a*is positive in the reddirection and negative in the green direction;b*is positive inthe yellow direction and negative in the blue direction;and L*is positive in the lightness direction and negative in thedarkness direction.E3083.1.2 colorimetry,nthe science of color measurement.E2843.1.3 in-service oil,nlubricating oil that is present in amachine that has been at operating temperature for at least onehour.3.1.4 membrane color,na visual rating of particulate on afilter membrane against ASTM Color Standards.3.1.5 membrane filter,na porous article of closely con-trolled pore size through which a liquid is passed to separatematter in suspension.3.2 Definitions of Terms Specific to This Standard:3.2.1 soot,nin internal combustion engines,sub-micronsize particles,primarily carbon,created in the combustionchamber as products of incomplete combustion.3.2.2 varnish,na thin,hard,lustrous,oil-insolubledeposit,composed primarily of organic residue,and mostreadily definable by color intensity.It is not easily removed by1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.C0.01 on Turbine Oil Monitoring,Problems and Systems.Current edition approved April 1,2021.Published April 2021.Originallyapproved in 2012.Last previous edition approved in 2018 as D7843 18.DOI:10.1520/D7843-21.2For 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.1wiping with a clean,dry,soft,lint-free wiping material and isresistant to saturated solvents.Its color may vary,but it usuallyappears in gray,brown,or amber hues.4.Summary of Test Method4.1 Insoluble deposits are extracted from an in-serviceturbine oil sample using a 47 mm,0.45 m membrane nitro-cellulose patch.The color of the patch is then analyzed usinga spect