ASTM_D_7412_-_21.pdf

Designation:D741221Standard Test Method forCondition Monitoring of Phosphate Antiwear Additives inIn-Service Petroleum and Hydrocarbon Based Lubricants byTrend Analysis Using Fourier Transform Infrared(FT-IR)Spectrometry1This standard is issued under the fixed designation D7412;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 phosphate antiwearadditives in in-service petroleum and hydrocarbon based lubri-cants such as various types of engine oils,hydraulic oils,andother lubricants that are formulated for protection against wear.Typical phosphate antiwear additives include zinc dialkyl-dithiophosphates,trialkyl phosphates,and triaryl phosphates.1.2 This test method uses Fourier Transform Infrared(FT-IR)spectrometry for monitoring of phosphate antiwear addi-tive depletion in in-service petroleum and hydrocarbon basedlubricants as a result of normal machinery operation.Monitor-ing the depletion of phosphate antiwear additives in in-servicelubricants can indicate unusual wear or severe operatingconditions of the machine.This test method is designed as afast,simple spectroscopic check for monitoring of phosphateantiwear additives in in-service petroleum and hydrocarbonbased lubricants with the objective of helping diagnose theoperational condition of the machine based on measuring thelevel of phosphate antiwear additives in the oil.1.3 Acquisition of FT-IR spectral data for measuring phos-phate antiwear additives in in-service oil and lubricant samplesis described in Practice D7418.In this test method,measure-ment and data interpretation parameters for phosphate antiwearadditives using both direct trend analysis and differential(spectral subtraction)trend analysis are presented.1.4 This test method is based on trending of spectralchanges associated with phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants.Warningsor alarm limits can be set on the basis of a fixed minimumvalue for a single measurement or,alternatively,can be basedon a rate 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-timeter).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 changes in the level ofphosphate antiwear additives to 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 D7412 18.DOI:10.1520/D7412-21.2The 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 St