1、Designation: E2412 10Standard Practice forCondition Monitoring of In-Service Lubricants by TrendAnalysis Using Fourier Transform Infrared (FT-IR)Spectrometry1This standard is issued under the fixed designation E2412; the number immediately following the designation indicates the year oforiginal adop
2、tion 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 practice covers the use of FT-IR in monitoringadditive depletion, c
3、ontaminant buildup and base stock degra-dation in machinery lubricants, hydraulic fluids and other fluidsused in normal machinery operation. Contaminants monitoredinclude water, soot, ethylene glycol, fuels and incorrect oil.Oxidation, nitration and sulfonation of base stocks are moni-tored as evide
4、nce of degradation. The objective of this moni-toring activity is to diagnose the operational condition of themachine based on fault conditions observed in the oil. Mea-surement and data interpretation parameters are presented toallow operators of different FT-IR spectrometers to compareresults by e
5、mploying the same techniques.1.2 This practice is based on trending and distributionresponse analysis from mid-infrared absorption measurements.While calibration to generate physical concentration units maybe possible, it is unnecessary or impractical in many cases.Warning or alarm limits (the point
6、 where maintenance actionon a machine being monitored is recommended or required)can be determined through statistical analysis, history of thesame or similar equipment, round robin tests or other methodsin conjunction with correlation to equipment performance.These warning or alarm limits can be a
7、fixed maximum orminimum value for comparison to a single measurement or canalso be based on a rate of change of the response measured(1).2This practice describes distributions but does not precludeusing rate-of-change warnings and alarms.NOTE 1It is not the intent of this practice to establish or re
8、commendnormal, cautionary, warning or alert limits for any machinery. Such limitsshould be established in conjunction with advice and guidance from themachinery manufacturer and maintenance group.1.3 Spectra and distribution profiles presented herein are forillustrative purposes only and are not to
9、be construed asrepresenting or establishing lubricant or machinery guidelines.1.4 This practice is designed as a fast, simple spectroscopiccheck for condition monitoring of in-service lubricants and canbe used to assist in the determination of general machineryhealth through measurement of propertie
10、s observable in themid-infrared spectrum such as water, oil oxidation, and othersas noted in 1.1. The infrared data generated by this practice istypically used in conjunction with other testing methods. Forexample, infrared spectroscopy cannot determine wear metallevels or any other type of elementa
11、l analysis. The practice aspresented is not intended for the prediction of lubricantphysical properties (for example, viscosity, total base number,total acid number, etc.). This practice is designed for monitor-ing in-service lubricants and can aid in the determination ofgeneral machinery health and
12、 is not designed for the analysis oflubricant composition, lubricant performance or additive pack-age formulations.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafet
13、y 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:3D445 Test Method for Kinematic Vi
14、scosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2896 Test Method for Base Number of Petroleum Prod-ucts by Potentiometric Perchloric Acid TitrationD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5185 Test Method for Determination of Additive Ele
15、-ments, Wear Metals, and Contaminants in Used Lubricat-ing Oils and Determination of Selected Elements in Base1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.96 onIn-Service Lubricant Testing and
16、Condition Monitoring Services.Current edition approved May 1, 2010. Published June 2010. Originallyapproved in 2004. Last previous edition approved in 2004 as E241204.DOI:10.1520/E2412-10.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced
17、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
18、ohocken, PA 19428-2959, United States.Oils by Inductively Coupled Plasma Atomic EmissionSpectrometry (ICP-AES)D6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Coulo-metric Karl Fischer TitrationE131 Terminology Relating to Molecular Spectroscopy
19、E168 Practices for General Techniques of Infrared Quanti-tative AnalysisE1421 Practice for Describing and Measuring Performanceof Fourier Transform Mid-Infrared (FT-MIR) Spectrom-eters: Level Zero and Level One TestsE1655 Practices for Infrared Multivariate QuantitativeAnalysis2.2 ISO Standard:4ISO
20、13372 Condition monitoring and diagnostics of ma-chines - Vocabulary3. Terminology3.1 DefinitionsFor definitions of terms relating to infraredspectroscopy used in this practice, refer to Terminology E131.3.2 Definitions:3.2.1 Fourier transform infrared (FT-IR) spectrometry,na form of infrared spectr
21、ometry in which an interferogramis obtained; this interferogram is then subjected to a Fouriertransform to obtain an amplitude-wavenumber (or wavelength)spectrum. E1313.3 Definitions of Terms Specific to This Standard:3.3.1 condition monitoring, na field of technical activityin which selected physic
22、al parameters associated with anoperating machine are periodically or continuously sensed,measured and recorded for the interim purpose of reducing,analyzing, comparing and displaying the data and informationso obtained and for the ultimate purpose of using interim resultto support decisions related
23、 to the operation and maintenanceof the machine (ISO 13372).3.3.2 in-service oil, nas applied in this practice, a lubri-cating oil that is present in a machine which has been atoperating temperature for at least one hour.3.3.2.1 DiscussionSampling a in-service oil after at leastone hour of operation
24、 will allow for the measurement of a basepoint for later trend analysis.3.3.2.2 DiscussionAny subsequent addition of lubricant(for example, topping off) may change the trending baseline,which may lead to erroneous conclusions.3.3.3 machinery health, na qualitative expression of theoperational status
25、 of a machine sub-component, component orentire machine, used to communicate maintenance and opera-tional recommendations or requirements in order to continueoperation, schedule maintenance or take immediate mainte-nance action.3.3.4 new oil, nan oil taken from the original manufac-turers packaging,
26、 prior to being added to machinery.3.3.5 reference oil, nsee new oil.3.3.6 trend analysis, nas applied in this practice, moni-toring of the level and rate of change over operating time ofmeasured parameters (1).4. Summary of Practice4.1 Periodic samples are acquired from the engine ormachine being m
27、onitored. An infrared absorbance spectrum ofthe sample is acquired, typically covering the range of 4000 to550 cm-1, with sufficient signal-to-noise (S/N) ratio to measureabsorbance areas of interest. Exact data acquisition parameterswill vary depending on instrument manufacturer but mostsystems sho
28、uld be able to collect an absorbance spectrumadequate for most measurements in less than one minute.Features in the infrared spectrum indicative of the molecularlevel components of interest (1,7) (that is, water, fuel, anti-freeze, additive, degradation, and so forth) are measured andreported. Condi
29、tion alerts and alarms can then be triggeredaccording to both the level and the trends from the monitoredsystem.5. Significance and Use5.1 Periodic sampling and analysis of lubricants have longbeen used as a means to determine overall machinery health.Atomic emission (AE) and atomic absorption (AA)
30、spectro-scopy are often employed for wear metal analysis (for ex-ample, Test Method D5185). A number of physical propertytests complement wear metal analysis and are used to provideinformation on lubricant condition (for example, Test MethodsD445, D2896, and D6304). Molecular analysis of lubricantsa
31、nd hydraulic fluids by FT-IR spectroscopy produces directinformation on molecular species of interest, including addi-tives, fluid breakdown products and external contaminants, andthus complements wear metal and other analyses used in acondition monitoring program (1,3-7).6. Apparatus6.1 Required Co
32、mponents:6.1.1 Fourier Transform Infrared Spectrometer (FT-IR)Instrument is configured with a source, beamsplitter anddetector to adequately cover the mid-infrared range of 4000cm-1to 550 cm-1. Most work has been done on systems usinga room temperature deuterated triglycine sulfate (DTGS)detector, a
33、ir-cooled source and Germanium coating on Potas-sium Bromide (Ge/KBr) beamsplitter. Alternate source, beam-splitter and detector combinations covering this range arecommercially available but have not been investigated for usein this practice. Other detectors may be suitable but should beused with c
34、aution. In particular, liquid nitrogen cooled Mer-cury Cadmium Telluride (MCT) detectors are known to exhibitsignificant nonlinearities.6.1.2 Infrared Liquid Transmission Sampling CellSampling cells can be constructed of zinc selenide (ZnSe),barium fluoride (BaF2), potassium bromide (KBr), or others
35、uitable window material, with a pathlength of 0.1 mm (100m), parallel (3to5%w/wsolids). As acondition limit (soot) has already triggered, action should beFIG. 1 Example of Carbonyl Containing Components in New OilFormulationsE2412 105taken irrespective of water. Exact quantitative measurement ofsoot
36、 is difficult (that is, % w/w) due to multiple infraredcontributing factors as well as the many different soot mea-surement methods available.A1.2.2 Soot:A1.2.2.1 Soot loading is measured from the baseline offsetat 2000 cm-1as described in TableA1.1. Fig.A1.2 shows someexamples of spectra showing lo
37、w, intermediate, high and veryhigh soot loading levels (increasing levels from 1 through 5).A1.2.2.2 Soot InterferenceHigh water levels have beenobserved to interfere with the measurement of soot in internalcombustion engine crankcases. However, this interference doesnot become significant until the
38、 water level is on the order of5 % (50 000 ppm), levels which will immediately condemnthe lubricant and require immediate maintenance action irre-spective of any other indicators.A1.2.3 Oxidation, Nitration and Sulfation:A1.2.3.1 Unlike the previous examples, oxidation, nitrationand sulfation breakd
39、own products in crankcase oils cannot beeasily quantified by comparison to pure prepared standards.Here, there are a large number of different oxidation andnitration compounds that can be produced and gradually buildup in the oil. Fig. A1.3 shows the measurement areas foroxidation and nitration prod
40、uct buildup monitoring, with thesulfation region highlighted in Fig. A1.4.A1.2.3.2 Oxidation, Nitration and SulfationInterferencesAs in the soot measurement, very high waterlevels can generate false positives for oxidation and nitration.However, water levels of this magnitude will immediatelycondemn
41、 the lubricant. Very high (5 %) glycol levels in acrankcase oil may start interfering with sulfation measurement,but again contaminant levels of this magnitude would dictateimmediate maintenance action. Various additive packages,such as detergents, dispersants, antioxidants, overbase addi-tives, etc
42、. may also generate significant absorbance in thecondition monitoring regions of interest. Blends of petroleumlubricants with significant amounts of ester, whether part of thebase-stock package or as an additive, will absorb strongly inthe oxidation area. These lubricants are not presented at thisti
43、me.A1.2.4 Fuel Contamination:A1.2.4.1 The possibility of fuel contamination may beindicated in diesel crankcase lubricants by measuring the peakat 810 cm-1. Spectral characteristics of diesel (Figs. A1.5 andA1.6) and other fuels noted in Table A1.1 have been found tovary. Work is currently active on
44、 other IR measurement areasand techniques. The measurement listed can be used as aguideline but is not intended to be the only infrared based fuelcontamination measurement. An independent test, such asviscosity change, flash point, or gas chromatography can beused to confirm an indication of fuel pr
45、esence in the FT-IRspectrum of the oil.A1.2.5 Glycol Antifreeze Contamination:A1.2.5.1 Glycol contamination is monitored in diesel crank-case lubricants by measuring the carbon-oxygen stretch regionas noted in Table A1.1. Spectral characteristics of glycolcontamination are shown in Fig. A1.6.A1.2.5.
46、2 Ethylene glycol will interfere with the ability toaccurately quantify water level when present since it alsocontains hydroxyl groups. However, the converse is not truesince glycol has other spectral features that are used fordetection and quantification. Therefore, when glycol is present,water can
47、 be detected but not reliably quantified using FT-IRspectroscopy. This is not considered a problem because of thegreater significance the presence of glycol has to engineoperation. As with fuel, the presence of glycol can be con-firmed by gas chromatography or a colorimetric test, or morecommonly, c
48、orroborated using elemental analysis results forsodium and boron.A1.3 Extreme Pressure (EP) Fluids (Typically PetroleumGear or Hydraulic Fluids):A1.3.1 In addition to the above crankcase oil analysis,condition monitoring of gear and hydraulic oil is also widelyapplied. In these systems, the most com
49、mon parametersmeasured are water contamination and oxidative breakdown ofthe oil, which are presented in Table A1.2.A1.3.2 Water:A1.3.2.1 As water is the most common contaminant incrankcase oils, it is also the most common contaminant ingearboxes and hydraulic systems. In these systems, unlike thecrankcase oils, however, interactions between water and the EPadditives alter the infrared response, and thus water is mea-sured differently than in the crankcase lubricants. Fig. A1.7demonstrates this different response of water. Water contami-nation is manifested as a gen
