ASTM_D_7843_-_12.pdf

Designation:D784312Standard 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.Scope1.1 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 CIE LAB scale.1.2 This test method is not appropriate for turbine oils withdyes.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 and determine the applica-bility of regulatory limitations prior to use.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 and Gas TurbinesE177 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(for example,an engine,gearbox,transformer,or turbine).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 varnish,na thin,hard,lustrous,oil-insolubledeposit,composed primarily of organic residue,and mostreadily definable by color intensity.It is not easily removed bywiping 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-micron membranenitro-cellulose patch.The color of the patch is then analyzedusing a spectrophotometer and the results are reported as a Evalue in the CIE LAB scale.5.Significance and Use5.1 This test can be a guide to end-users on the formation oflubricant-generated,insoluble deposits.5.2 The results from this test are intended to be used as acondition monitoring trending tool as part of a comprehensiveprogram,as outlined in standards such as Practice D4378.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.C0 on Turbine Oils.Current edition approved Dec.1,2012.Published January 2013.DOI:10.1520/D7843-12.2For 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 States1 6.Apparatus6.1 Variations of apparatus,particularly with respect to filtermembranes and vacuum pump setting,can affect the testresults significantly.6.2 When the user of this test method uses an alternatemembrane filter,it is incumbent upon them to establish that thealternate filter will give equal results.6.3 Required Apparatus:6.3.1 Membrane Filter,47 mm nitro-cellulose,0.45-m.6.3.2 Forceps,smooth-tip.6.3.3 Borosilicate Filter Holder.6.3.4 Borosilicate Filtering Flask.6.3.5 Wash Bottle equipped with 0.22 micron membranes.6.3.6 Vacuum Source,capable of maintaining a vacuum of71 kPa 6 5 kPa.6.3.7 Graduated cylinder,150200 mL.6.3.8 Beaker,100250 mL.6.3.9 Petri dish.6.3.10 Spectrophotometer,with capabilities of analyzing astandard 15 mm target with a 0/45 measuring geometry,10observer,10 nm spectral intervals minimum resolution,thevisible spectral range of 400700 nm and CIELAB measuringindices.7.Reagents and Materials7.1 Petroleum Spirit(also known as petroleum ether or IPPe