ASTM_D_7415_-_21.pdf

Designation:D741521Standard Test Method forCondition Monitoring of Sulfate By-Products in In-ServicePetroleum and Hydrocarbon Based Lubricants by TrendAnalysis Using Fourier Transform Infrared(FT-IR)Spectrometry1This standard is issued under the fixed designation D7415;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 monitoring sulfate by-productsin in-service petroleum and hydrocarbon based diesel crank-case engine and motor oils that have a sulfur content of greaterthan 500 ppm.This test method should not be employed whenlow-sulfur fuels are used for combustion.1.2 This test method uses Fourier Transform Infrared(FT-IR)spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubri-cants as a result of normal machinery operation.Sulfateby-products can result from the introduction of sulfur fromcombustion or from the oxidation of sulfur-containing base oiladditives.This test method is designed as a fast,simplespectroscopic check for monitoring of sulfate by-products inin-service petroleum and hydrocarbon based lubricants withthe objective of helping diagnose the operational condition ofthe machine based on measuring the level of sulfate by-products in the oil.1.3 Acquisition of FT-IR spectral data for measuring sulfateby-products in in-service oil and lubricant samples is describedin Practice D7418.In this test method,measurement and datainterpretation parameters for sulfate by-products using bothdirect trend analysis and differential(spectral subtraction)trendanalysis are presented.1.4 This test method is based on trending of spectralchanges associated with sulfate by-products of in-servicepetroleum and hydrocarbon based lubricants.Warnings oralarm limits can be set on the basis of a fixed minimum valuefor a single measurement or,alternatively,can be based on arate of change of the response measured,see Ref(1).21.4.1 For direct trend analysis,values are recorded directlyfrom absorption spectra and reported in units of absorbance per0.1 mm pathlength.1.4.2 For differential trend analysis,values are recordedfrom the differential spectra(spectrum obtained by subtractionof the absorption spectrum of the reference oil from that of thein-service oil)and reported in units of 100*absorbance per0.1 mm pathlength(or equivalently absorbance units per cen-timetre).1.4.3 In either case,maintenance action limits should bedetermined through statistical analysis,history of the same orsimilar equipment,round robin tests,or other methods inconjunction with the correlation of sulfate by-product changesto equipment performance.NOTE1It is not the intent of this test method to establish orrecommend normal,cautionary,warning,or alert limits for any machinery.Such limits should be established in conjunction with advice and guidancefrom the machinery manufacturer and maintenance group.1.5 This test method is for petroleum and hydrocarbonbased lubricants and is not applicable for ester based oils,including polyol esters or phosphate esters.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6.1 ExceptionThe unit for wave numbers is cm-1.1.7 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.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.96.03 on FTIR Testing Practices and Techniques Related toIn-Service Lubricants.Current edition approved Dec.1,2021.Published January 2022.Originallyapproved in 2009.Last previous edition approved in 2018 as D7415 18.DOI:10.1520/D7415-21.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.*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.1Development of International Standards,Guides and Recom-mendations issued b