1、Designation: E2412 10 (Reapproved 2018)Standard 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 ye
2、ar 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 practice covers the use of FT-IR in monitoringadd
3、itive depletion, contaminant 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 m
4、oni-tored as evidence 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 c
5、ompareresults by employing 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
6、 limits (the point 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 alar
7、m limits can be a 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
8、to establish or recommendnormal, 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 on
9、ly and are not to 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 measur
10、ement of properties 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 othe
11、r type of elemental 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 ma
12、chinery health and 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 addre
13、ss 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.1.7 This international standard was develo
14、ped in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.1This practice is u
15、nder the jurisdiction of ASTM Committee D02 on PetroleumProducts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.96.03 on FTIR Testing Practices and Techniques Related to In-ServiceLubricants.Current edition approved June 1, 2018. Published June 2018. Originallyap
16、proved in 2004. Last previous edition approved in 2010 as E2412 10.DOI:10.1520/E2412-10R18.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
17、This 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
18、 (TBT) Committee.12. Referenced Documents2.1 ASTM Standards:3D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D2896 Test Method for Base Number of Petroleum Productsby Potentiometric Perchloric Acid TitrationD4057 Practice for Manual Sa
19、mpling of Petroleum andPetroleum ProductsD5185 Test Method for Multielement Determination ofUsed and Unused Lubricating Oils and Base Oils byInductively Coupled Plasma Atomic Emission Spectrom-etry (ICP-AES)D6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Ad
20、ditives by Cou-lometric Karl Fischer TitrationE131 Terminology Relating to Molecular SpectroscopyE168 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 Le
21、vel One TestsE1655 Practices for Infrared Multivariate QuantitativeAnalysis2.2 ISO Standard:4ISO 13372 Condition monitoring and diagnostics ofmachinesVocabulary3. Terminology3.1 DefinitionsFor definitions of terms relating to infraredspectroscopy used in this practice, refer to Terminology E131.3.2
22、Definitions:3.2.1 Fourier transform infrared (FT-IR) spectrometry, naform of infrared spectrometry in which an interferogram isobtained; this interferogram is then subjected to a Fouriertransform to obtain an amplitude-wavenumber (or wavelength)spectrum. E1313.3 Definitions of Terms Specific to This
23、 Standard:3.3.1 condition monitoring, na field of technical activityin which selected physical 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 information
24、so obtained and for the ultimate purpose of using interim resultto support decisions related 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 le
25、ast one hour.3.3.2.1 DiscussionSampling a in-service oil after at leastone hour of operation 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 erro
26、neous conclusions.3.3.3 machinery health, na qualitative expression of theoperational status 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
27、mainte-nance action.3.3.4 new oil, nan oil taken from the original manufactur-ers packaging, 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 (
28、1).4. Summary of Practice4.1 Periodic samples are acquired from the engine ormachine being monitored. An infrared absorbance spectrum ofthe sample is acquired, typically covering the range of4000 cm1to 550 cm1, with sufficient signal-to-noise (S/N)ratio to measure absorbance areas of interest. Exact
29、 dataacquisition parameters will vary depending on instrumentmanufacturer but most systems should be able to collect anabsorbance spectrum adequate for most measurements in lessthan one minute. Features in the infrared spectrum indicative ofthe molecular level components of interest (1,2) (that is,
30、water,fuel, antifreeze, additive, degradation, and so forth) are mea-sured and reported. Condition alerts and alarms can then betriggered according to both the level and the trends from themonitored system.5. Significance and Use5.1 Periodic sampling and analysis of lubricants have longbeen used as
31、a means to determine overall machinery health.Atomic emission (AE) and atomic absorption (AA) spectros-copy are often employed for wear metal analysis (for example,Test Method D5185). A number of physical property testscomplement wear metal analysis and are used to provideinformation on lubricant co
32、ndition (for example, Test MethodsD445, D2896, and D6304). Molecular analysis of lubricantsand hydraulic fluids by FT-IR spectroscopy produces directinformation on molecular species of interest, includingadditives, fluid breakdown products and external contaminants,and thus complements wear metal an
33、d other analyses used in acondition monitoring program (1,3-2).6. Apparatus6.1 Required Components:6.1.1 Fourier Transform Infrared Spectrometer (FT-IR)Instrument is configured with a source, beamsplitter anddetector to adequately cover the mid-infrared range of4000 cm1to 550 cm1. Most work has been
34、 done on systemsusing a room temperature deuterated triglycine sulfate (DTGS)3For 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 ont
35、he ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.E2412 10 (2018)2detector, air-cooled source and Germanium coating on Potas-sium Bromide (Ge/KBr) beamsplitter. Alternate source, beam-splitter and detector c
36、ombinations covering this range arecommercially available but have not been investigated for usein this practice. Other detectors may be suitable but should beused with caution. In particular, liquid nitrogen cooled Mer-cury Cadmium Telluride (MCT) detectors are known to exhibitsignificant nonlinear
37、ities.6.1.2 Infrared Liquid Transmission Sampling CellSampling cells can be constructed of zinc selenide (ZnSe),barium fluoride (BaF2), potassium bromide (KBr), or othersuitable window material, with a pathlength of 0.1 mm(100 m), parallel ( 3 % to 5 % w/w solids). As acondition limit (soot) has alr
38、eady triggered, action should betaken irrespective of water. Exact quantitative measurement ofsoot is difficult (that is, % ww) 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 baseli
39、ne offsetat 2000 cm1as described in TableA1.1. Fig.A1.2 shows someexamples of spectra showing low, 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 inter
40、nalcombustion engine crankcases. However, this interference doesnot become significant until the 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, Nitrati
41、on and Sulfation:A1.2.3.1 Unlike the previous examples, oxidation, nitrationand sulfation breakdown 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 gra
42、dually buildup in the oil. Fig. A1.3 shows the measurement areas foroxidation and nitration product 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 posit
43、ives for oxidation and nitration.However, water levels of this magnitude will immediatelycondemn 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. V
44、arious additive packages,such as detergents, dispersants, antioxidants, overbaseadditives, etc. 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 add
45、itive, will absorb strongly inthe oxidation area. These lubricants are not presented at thistime.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 an
46、dA1.6) and other fuels noted in Table A1.1 have been found tovary. Work is currently active on 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 asvisco
47、sity change, flash point, or gas chromatography can beused to confirm an indication of fuel presence 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
48、 in Table A1.1. Spectral characteristics of glycolcontamination are shown in Fig. A1.6.A1.2.5.2 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 featu
49、res that are used fordetection and quantification. Therefore, when glycol is present,water can 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, corroborated 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
