ASTM_E_2412-102018_.pdf

This international standard was developed incordancewith internationally recognized principlesstandardization established in the Decisionon Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.Designation:E2412-10(Reapproved 2018)NTERNATIONALStandard Practice forCondition Monitoring of In-Service Lubricants by TrendAnalysis Using Fourier Transform Infrared(FT-IR)SpectrometryThis standard is issued under the fixed designation E2412: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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.3 Spectra and distribution profiles presented herein are for1.1 This practice covers the use of FT-IR in monitoringillustrative purposes only and are not to be construed asadditive depletion,contaminant buildup and base stock degra-representing or establishing lubricant or machinery guidelines.dation in machinery lubricants,hydraulic fluids and other fluids1.4 This practice is designed as a fast,simple spectroscopicused in normal machinery operation.Contaminants monitoredcheck for condition monitoring of in-service lubricants and caninclude water,soot,ethylene glycol,fuels and incorrect oil.be used to assist in the determination of general machineryOxidation,nitration and sulfonation of base stocks are moni-health through measurement of properties observable in thetored as evidence of degradation.The objective of this moni-mid-infrared spectrum such as water,oil oxidation,and otherstoring activity is to diagnose the operational condition of theas noted in 1.1.The infrared data generated by this practice ismachine based on fault conditions observed in the oil.Mea-typically used in conjunction with other testing methods.Forsurement and data interpretation parameters are presented toexample,infrared spectroscopy cannot determine wear metalallow operators of different FI-IR spectrometers to comparelevels or any other type of elemental analysis.The practice asresults by employing the same techniques.presented is not intended for the prediction of lubricant1.2 This practice is based on trending and distributionphysical properties(for example,viscosity,total base number,response analysis from mid-infrared absorption measurements.total acid number,etc.).This practice is designed for monitor-While calibration to generate physical concentration units maying in-service lubricants and can aid in the determination ofbe possible,it is unnecessary or impractical in many cases.general machinery health and is not designed for the analysis ofWarning or alarm limits(the point where maintenance actionlubricant composition,lubricant performance or additive pack-on a machine being monitored is recommended or required)age formulations.can be determined through statistical analysis,history of thesame or similar equipment,round robin tests or other methods1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisin conjunction with correlation to equipment performance.These warning or alarm limits can be a fixed maximum orstandard.minimum value for comparison to a single measurement or can1.6 This standard does not purport to address all of thealso be based on a rate of change of the response measuredsafety concerns,if any,associated with its use.It is the(1).This practice describes distributions but does not precluderesponsibility of the user of this standard to establish appro-using rate-of-change warnings and alarms.priate safery,health,and environmental practices and deter-Nor 1-It is not the intent of this practice to establish or recommendmine the applicability of regulatory limitations prior to use.normal,cautionary.waming or alert limits for any machinery.Such limitsshould be established in conjunction with advice and guidance from the1.7 This international standard was developed in accor-machinery manufacturer and maintenance group.dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-This practice is under the jurisdiction of ASTM Committee D02 on Petroleummendations issued by the World Trade Organization TechnicalProducts.Liquid Fuels.and Lubricants and is the direct responsibility of Subcom-Barriers to Trade(TBT)Committee.mittee D02.96.03 on FTIR Testing Practices and Techniques Related to In-ServiceLubricants.Current edition approved June 1.2018.Published June 2018.Originallyapproved in 2004.Last previous edition approved in 2010 as E2412-10.D0L:10.1520/E2412-10R18.2 The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM Intemational,100 Barr Harbor Drive,PO Box C700.West Conshohocken,PA 19428-2959.United StatesE2412-10(2018)2.Referenced Documentsone hour of operation will allow for the measurement of a base2.1 ASTM Standards:point for later trend analysis.D445 Test Method for Kinematic Viscosity of Transparent3.3.2.2 Discussion-Any subsequent addition of lubricantand Opaque Liquids(and Calculation of Dynamic Viscos-(for example,topping off)may change the trending baseline,ity)which may lead to erroneous conclusions.D2896 Test Method for Base Number of Petroleum Products3.3.3 machinery health,n-a qualitative expression of theby Potentiometric Perchloric Acid Titrationoperational status of a machine sub-component,component orD4057 Practice for Manual Sampling of Petroleum andentire machine,used to communicate maintenance and opera-Petroleum Productstional recommendations or requirements in order to continueD5185 Test Method for Multielement Determination ofoperation,schedule maintenance or take immediate mainte-Used and Unused Lubricating Oils and Base Oils bynance action.Inductively Coupled Plasma Atomic Emission Spectrom-3.3.4 new oil,n-an oil taken from the original manufactur-etry(ICP-AES)ers packaging,prior to being added to machinery.D6304 Test Method for Determination of Water in Petro-leum Products,Lubricating Oils,and Additives by Cou-3.3.5 reference oil,n-see new oil.lometric Karl Fischer Titration3.3.6 trend analysis,n-as applied in this practice,moni-E131 Terminology Relating to Molecular Spectroscopytoring of the level and rate of change over operating time ofE168 Practices for General Techniques of Infrared Quanti-measured parameters(1).tative AnalysisE1421 Practice for Describing and Measuring Performance4.Summary of Practiceof Fourier Transform Mid-Infrared(FT-MIR)Spectrom-eters:Level Zero and Level One Tests4.1 Periodic samples are acquired from the engine orE1655 Practices for Infrared Multivariate Quantitativemachine being monitored.An infrared absorbance spectrum ofAnalysisthe sample is acquired,typically covering the range of4000 cm-to 550 cm,with sufficient signal-to-noise(S/N)2.2 ISO Standard:ratio to measure absorbance areas of interest.Exact dataISO 13372 Condition monitoring and diagnostics ofacquisition parameters will vary depending on instrumentmachines-Vocabularymanufacturer but most systems should be able to collect anabsorbance spectrum adequate for most measurements in less3.Terminologythan one minute.Features in the infrared spectrum indicative of3.1 Definitions-For definitions of terms relating to infraredthe molecular level components of interest(1,2)(that is,water,spectroscopy used in this practice,refer to Terminology E131.fuel,antifreeze,additive,degradation,and so forth)are mea-3.2 Definitions:sured and reported.Condition alerts and alarms can then be3.2.1 Fourier transform infrared(FT-IR)spectrometry,n-atriggered according to both the level and the trends from theform of infrared spectrometry in which an interferogram ismonitored system.obtained;this interferogram is then subjected to a Fouriertransform to obtain an amplitude-wavenumber(or wavelength)5.Significance and Usespectrum.E1315.1 Periodic sampling and analysis of lubricants have long3.3 Definitions of Terms Specific to This Standard:been used as a means to determine overall machinery health.3.3.1 condition monitoring,n-a field of technical activityAtomic emission(AE)and atomic absorption(AA)spectros-in which selected physical parameters associated with ancopy are often employed for wear metal analysis(for example,operating machine are periodically or continuously sensed,Test Method D5185).A number of physical property testsmeasured and recorded for the interim purpose of reducing,complement wear metal analysis and are used to provideanalyzing,comparing and displaying the data and informationinformation on lubricant condition(for example,Test Methodsso obtained and for the ultimate purpose of using interim resultD445,D2896,and D6304).Molecular analysis of lubricantsto support decisions related to the operation and maintenanceand hydraulic fluids by FT-IR spectroscopy produces directof the machine(ISO 13372).information on molecular species of interest,including3.3.2 in-service oil,n-as applied in this practice,a lubri-additives,fluid breakdown products and external contaminants,and thus complements wear metal and other analyses used in acating oil that is present in a machine which has been atoperating temperature for at least one hour.condition monitoring program(1,3-2).3.3.2.1 Discussion-Sampling a in-service oil after at least6.Apparatus6.1 Required Components:For referenced ASTM standards,visit the ASTM website,www.astm.org,or6.1.1 Fourier Transform Infrared Spectrometer(FT-IR)-contact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMInstrument is configured with a source,beamsplitter andStandards volume information,refer to the standards Document Summary page onthe ASTM website.detector to adequately cover the mid-infrared range of4 Available from American National Standards Institute(ANSI),25 W.43rd St.,4000 cm-to 550 cm.Most work has been done on systems4th Floor,New York,NY 10036,http:/www.ansi.orgusing a room temperature deuterated triglycine sulfate(DTGS)2E2412-10(2018)detector,air-cooled source and Germanium coating on Potas-pump types,tubing and transmission cells for this type ofsium Bromide(Ge/KBr)beamsplitter.Alternate source,beam-application.It should be noted that non-homogeneity mightsplitter and detector combinations covering this range areoccur if the oils are left standing for too mercially available but have not been investigated for use6.2.2 Filter-The use of a particulate filter(for example.in this practice.Other detectors may be suitable but should be0.090 mm)to trap large particles is strongly recommended toused with caution.In particular,liquid nitrogen cooled Mer-prevent cell clogging when a pumping system is used.If acury Cadmium Telluride(MCT)detectors are known to exhibitparticulate filter is not used,the cell should be back-flushedsignificant nonlinearities.regularly to prevent clogging.6.1.2 Infrared Liquid Transmission Sampling Cell-6.2.3 Sealed Sample Compartment-The system configura-Sampling cells can be constructed of zinc selenide(ZnSe).tion should be consistent with preventing harmful,flammablebarium fluoride(BaF,),potassium bromide(KBr),or otheror explosive vapors from reaching the IR source.suitable window material,with a pathlength of 0.1 mm6.2.4 Hydrocarbon Leak Alarm-When a sample pumping(100 um),parallel(0.5 variance)cell spacer.Acceptablesystem is used,an independent flammable vapor sensor andpathlength ranges are from 0.080 mm to 0.120 mm.Outsidealarm system should be used to alert the operator when a leakthis range,poor sensitivity or data nonlinearity can occur.Foroccurs in the tubing,connectors or transmission cell.Thisthe data provided in this document,the cells used were ZnSe.alarm system is strongly recommended when a pumpingNaCl,or KBr as the measurements ranged from 4000 cm-tosystem is used to pump samples and wash solvents into an700 cm.Some cell material information is given below.enclosed area.Transmission6.2.5 Check Fluid-A check fluid or quality control fluidMaterialCommentsRange,cm-1can be analyzed as needed for individual laboratory qualityZnSesee 6.1.2.14000-550control and procedure issues and for comparison to otherKBrsusceptible to water damage4000-400NaClsusceptible to water damage4000-650laboratories.One IR manufacturer has used heptane.A checkBaFammonium salts can damage4000-850sample should be a material that provides consistent resultsCaF2ammonium salts can damage4000-1100using the methods presented in the annexes to this practice.TheResults should be corrected to 0.100 mm pathlength topurpose of this quality control fluid is to verify properaccount for cell path variation and improve data comparison tooperation of the FT-IR spectrometer/transmission cellother instruments using this binations,as well as any associated sample introduction6.1.2.1 Due to the large refractive index change when theand cleaning hardware.infrared beam passes from air into the ZnSe windows,fringereduction is necessary to provide consistent results.Fringe7.Sampling and Sample Handlingreduction can be achieved electronically,optically or mechani-7.1 Sample Acquisition-The objective of sampling is tocally for ZnSe cells.For further explanation,see Appendix X1.obtain a test specimen that is representative of the entireCare should be taken in selecting window materials to ensurequantity.Thus,laboratory samples should be taken in accor-that the desired parameters can be measured within thedance with the instructions in Practice D4057.transmission region of that material and compatibility with thespecific application;for example,salt windows(KBr,NaCl,7.2 Sample Preparation-No sample preparation is re-KCl)can be used and may not require fringe correction but arequired.Laboratory samples should be shaken or agitated tosusceptible to damage from water contamination in the oilensure a representative sample is taken from the bottle.Coates and Setti(3)have noted that oil nitration products canreact with salt windows,depositing compounds that are ob-8.Instrumentation Preparationserved in later samples.8.1 Spectral Acquisition Parameters:6.1.3 Cell Flushing/Cleaning Solvent-The ideal solvent to8.1.1 Spectral Resolution-8 cm or better(lower numericflush the cell between samples to minimize carryover shouldvalue).have no significant absorption in the condition monitoring8.1.2 Data Point Spacing Resolution-4 cm-or betterareas of interest and should dry quickly when air is pumped(lower numeric value).through the system.Typical wash solvents used for common8.1.3 Typical Range-4000 cm-to 550 cm-(see 6.1.2).petroleum and some synthetic lubricants are technical grade.8.1.4 Spectral Format-Absorbance as a function of wave-light aliphatic hydrocarbons such as heptane or cyclohexane.number.Other solvents may be required for more specialized synthetic8.1.5 Other Optical,Electronic Filtering and Interferogramlubricants.Health and safety issues on using,storing,andComputational Parameters-These parameters should be asdisposing of these solvents will not be covered here.Localrecommended by the manufacturer or as determined necessaryregulations and Material Safety Data Sheets(MSDS)should befor adequate measurement quality.Individual parameters andconsulted.settings will vary depending on instrument manufacturer but6.2 Optional Components:most FT-IR spectrometers should be able to collect an adequatespectrum in less than one minute.6.2.1 Sample Pumping System-A pumping system capableof transporting the sample to the transmission cell,emptyingNoTE 2-Identical scanning acquisition parameters should be used forthe cell and flushing the cell between samples may be used.all samples to be trended.Many commercial vendors offer various configurations of8.2 Background Collection:3E2412-10(2018)8.2.1 The single-beam background collection(empty sys-9.2.1 Petroleum based lubricants have their maximum ab-tem reference scanned and stored on an FT-IR spectrometer)sorbance in the 3000 cm to 2800 cm range(or transmit-should be performed frequently enough such that ambienttance value close to 0%T).changes in atmospheric water vapor levels and other changing9.2.2 Ester based lubricants have their maximum absor-ambient conditions do not significantly affect the samplebance in the 1390 cm to 1090 cm range(or transmittanceresults(see Practice E1421).The frequency of backgroundvalue close to 0%T).checks should be determined by the individual laboratoryconditions and sampling technique;for example,at the9.3 Sample System Cleaning and Checks-To ensure thecompletion of each run when an autosampler is used.minimum amount of sample cross-contamination or sample8.2.2 Note that changing water vapor levels will have thecarry-over,either a minimum volume of the next sample can bestrongest effect,as water vapor is a strong infrared absorber.Aflushed,or a volatile solvent can be flushed through the cell andwater vapor check may be included in the software to monitorthe cell dried.If the cell is dried,the amount of absorbancethe intensity of the water vapor in the single-beam backgroundfrom either the previous sample or residual wash solvent in thespectrum.For example,the water vapor bands superimposedsample cell can be checked.This check is performed by theon the single-beam spectrum at 1540 cm,1559 cm-,andsame spectral analysis operation as described above.The1652 cm may be measured relative to the average of baselinemaximum absorbance intensity should be below a presetpoints at 1609 cm-to 1582 cm-.Acceptable limits for opera-threshold in the monitoring region(that is,CH stretch intion can be set;for example,measured peaks due to waterpetroleum based fluids).For most petroleum and syntheticvapor superimposed on the single-beam background should notlubricants and wash solvents,this intensity will be less than 0.2be more than 10%of the single-beam intensity.absorbance units.The optimal threshold will depend upon the8.2.3 Most of the research and development work used inspecific system configuration,in that some systems are de-the development of this practice used a background collectionsigned to push-out the residual oil sample and wash solventat least every 2 h.Individual parameters and settings will varywith the next sample.The manufacturers suggestions anddepending on instrument manufacturer but most FT-IR spec-recommendations should be considered.trometers should be able to collect an adequate spectrum in less9.4 Data Processing-All spectra will be processed in unitsthan one minute.of absorbance as a function of wavenumber.Calculated data8.3 Cell Pathlength Check-A cell pathlength check ismust be corrected to the reference pathlength of 0.100 mmneeded to verify the pathlength consistency of the cell.Resultsprior to reporting to account for cell pathlength variation thatare referenced to 0.100 mm as mentioned in 6.1.2.This checkwill be seen in commercially available cells.Any other spectralis particularly important for water-soluble salt cell windowsdata treatment should occur prior to calculating results from the(for example,KBr).For systems using a fixed flow cell,thespectrum.check can be performed at the same time as the background9.4.1 Spectral data processing results can be trended di-collection.Different instrument manufacturers may use differ-rectly from the in-service oil spectrum(direct trending).Theent techniques for cell pathlength checks that may require theonly spectral data treatment is the correction of the spectrum oruse of a reference or calibration fluid(s).A fringe-based methodresults to the 0.100 mm reference pathlength and the applica-for determining cell pathlength is discussed in the appendix.tion of fringe reduction algorithms to the spectrum,if required.Manufacturers instructions and recommendations should be9.4.2 Spectral data processing results can also be obtainedconsidered.by spectral subtraction processing,which requires a reference9.Procedures,Calculation,and Reportingspectrum(spectral subtraction).Where spectral subtraction isused,processing of results is done from the difference spec-9.1 Sample Introduction-A representative sample is intro-trum that is generated by subtracting the appropriate new oilduced into the infrared transmission cell,either manually or byreference spectrum from the spectrum of the in-service oilan automatic pumping system.Autosamplers that hold asample.The in-service oil spectrum and new oil referencevariety of oil sample container sizes are available from severalspectrum must both be corrected to the reference pathlength ofmanufacturers.0.100 mm prior to subtraction and a 1:1 subtraction factor used.9.2 Sample Integrity Check-To ensure accurate and con-The subtracted spectral results can be trended over time andtreated in a manner similar to those collected using the directsistent results,the infrared spectrum of the sample should bechecked to verify that the cell is completely filled and that airinfrared trending method.bubbles passing through the cell during data collection are not9.4.2.1 The most commonly used reference is a sample ofaffecting the results.Multiple,automatic,computerized inter-new oil.If possible,the new oil should be from the same lotpretation methods exist for this procedure.A sample integrityand drum as the in-service oil.An alternate approach that mightcheck based on measurement of the absorbance intensity overyield a more representative reference would be to take a samplethe wavenumber range from 3000 cm to 1090 cm-is suit-of oil one hour after the oil has reached operating temperatures.able for multiple lubricant types.The exact absorbance inten-9.4.3 Post-analysis data treatment can use simple multipli-sity will depend on the spectral resolution and the pathlength ofers and other scaling techniques;for example,value 100atthe cell being used.The manufacturers suggestions andthe request of maintenance personnel for ease in evaluation andrecommendations should be considered.presentation(see Annex A1).4E2412-10(2018)9.5 Spectral Analysis of Sample Data-Selected spectralregions containing information relevant to condition monitor-ing are measured and reported.The regions analyzed arespecific to different lubricating fluid types.New oil sampleWould Compute as.4Oxidationparameters can be used as the point from which to trend whenValuesinitially implementing an analysis process for a lubricant type.15.6Statistical analysis shown in the annexes also provides ex-13.8amples.Details of the spectral analysis process can be found in11.7the annexes to this Practice.005四0-0308.610.Effects of Oil Formulation10.1 Differences in oil formulations can affect the resultsreported for the various measurements described in Annex Al.For example,Fig.I shows spectra of four 10W-30 oils in thecarbonyl region where oxidation is measured for petroleum.1lubricants.In this example,absorbances for carbonyl-containing additives in these unused oil formulations contrib-ute nearly a factor of 2 difference in the oxidation resultmeasured by direct trending.0-10.2 Results should be:18001700160010.2.1 Interpreted relative to values measured for unused oilWavenumbersof the same formulation,orFIG.1 Example of Carbonyl Containing Components in New Oil10.2.2 Trended directly from the component sample history.Formulations10.3 Distribution profiles for results for different oil formu-lations should typically not be combined unless justified byfield experience in condition monitoring programs.fuel;glycol;infrared;IR;lubricating oils;nitration;oxidation;11.Keywordspetroleum based extreme pressure lubricants;petroleum lubri-11.1 additive packages;base stock degradation;conditioncants;polyol ester synthetic lubricants;soot;sulfates;trendmonitoring;contamination;Fourier transform infrared;FT-IR;analysis;waterANNEXES(Mandatory Information)A1.MEASUREMENT OF MOLECULAR PARAMETERS IN VARIOUS SYSTEMS-DIRECT TRENDINGA1.1 This annex does not purport to discuss all lubricantgasoline is also possible but not as widely applied,as com-types.Measurement parameters for petroleum lubricants(forparatively few gasoline engines are enrolled in conditionexample,crankcase),extreme pressure petroleum lubricantsmonitoring programs.In addition,monitoring of the zincand polyol esters are presented.As data becomes available,dialkyldithiophosphate(ZDDP)based antiwear component ofother lubricant types can be added to the annex.the additive package is also possible.The most common FT-IRNoTE Al.1-It is not the intent of this practice to establish orcondition monitoring parameters for crankcase engines arerecommend normal,cautionary,warning or alert limits for any machinerypresented in Table Al.1,with some spectral measurementor fluids.Such limits should be established in conjunction with advice andexamples presented as a guide in using band areas.Throughoutguidance from the machinery manufacturer and maintenance group.these examples,the use of integrated band area is preferred asA1.2 Petroleum Lubricants(Typically Diesel Engines)noted in Practice E168 because it has been found to be moreMonitoring of diesel crankcase oil is one of the most commonaccurate than peak-height measurements because one is,inapplications of lubricant condition monitoring.Conditioneffect,averaging multipoint data.monitoring in these systems is divided into contaminantA1.2.1 Water:monitoring(typically water,soot,fuel,glycol)and oil degra-A1.2.1.1 Water contamination is monitored in diesel crank-dation monitoring(typically oxidation and nitration).Sulfationcase lubricants by measuring the hydrogen-bonded OH stretchdegradation products may arise from lubricant componentregion given in Table Al.1.An example of varying levels ofbreakdown but commonly arise from the by-products ofwater contamination is shown in Fig.A1.1.In the followingsulfur-containing diesel fuels.Measuring contamination fromexamples(except soot)the infrared spectrum is shaded down to5