1、Designation: D 7414 09Standard Test Method forCondition Monitoring of Oxidation in In-Service Petroleumand Hydrocarbon Based Lubricants by Trend AnalysisUsing Fourier Transform Infrared (FT-IR) Spectrometry1This standard is issued under the fixed designation D 7414; the number immediately following
2、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. Scope1.1 This test method cover
3、s monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as indiesel crankcase, motor, hydraulic, gear and compressor oils,as well as other types of lubricants that are prone to oxidation.1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monito
4、ring build-up of oxidation productsin in-service petroleum and hydrocarbon based lubricants as aresult of normal machinery operation. Petroleum and hydro-carbon based lubricants react with oxygen in the air to form anumber of different chemical species, including aldehydes,ketones, esters, and carbo
5、xylic acids. This test method isdesigned as a fast, simple spectroscopic check for monitoringof oxidation in in-service petroleum and hydrocarbon basedlubricants with the objective of helping diagnose the opera-tional condition of the machine based on measuring the level ofoxidation in the oil.1.3 A
6、cquisition of FT-IR spectral data for measuring oxida-tion in in-service oil and lubricant samples is described inPractice D 7418. In this test method, measurement and datainterpretation parameters for oxidation using both direct trendanalysis and differential (spectral subtraction) trend analysisar
7、e presented.1.4 This test method is based on trending of spectralchanges associated with oxidation of in-service petroleum andhydrocarbon based lubricants. Warnings or alarm limits can beset on the basis of a fixed minimum value for a singlemeasurement or, alternatively, can be based on a rate of ch
8、angeof 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 subtr
9、actionof the absorption spectrum of the reference oil from that of thein-service oil) and reported in units of 100*absorbance per 0.1mm pathlength (or equivalently absorbance units per centime-tre).1.4.3 In either case, maintenance action limits should bedetermined through statistical analysis, hist
10、ory of the same orsimilar equipment, round robin tests or other methods inconjunction with the correlation of oxidation changes toequipment performance.NOTE 1It is not the intent of this test method to establish orrecommend normal, cautionary, warning or alert limits for any machinery.Such limits sh
11、ould 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 un
12、its 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 standar
13、d 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:3D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D 664 Test Meth
14、od forAcid Number of Petroleum Productsby Potentiometric TitrationD 974 Test Method for Acid and Base Number by Color-Indicator TitrationD 2896 Test Method for Base Number of Petroleum Prod-ucts by Potentiometric Perchloric Acid TitrationD 4739 Test Method for Base Number Determination by1This test
15、method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.96 on In-Service Lubricant Testing and Condition Monitoring Services.Current edition approved July 1, 2009. Published August 2009.2The boldface numbers in pa
16、rentheses refer to a list of references at the end ofthis standard.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 onthe ASTM we
17、bsite.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Potentiometric Hydrochloric Acid TitrationD 5185 Test Method for Determination of Additive Ele-ments, Wear Metals, and Contaminants in Used Lubricat-ing Oils and Determination of
18、Selected Elements in BaseOils by Inductively Coupled Plasma Atomic EmissionSpectrometry (ICP-AES)D 6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Coulo-metric Karl Fischer TitrationD 7412 Test Method for Condition Monitoring of Phos-phate Antiw
19、ear Additives in In-Service Petroleum andHydrocarbon Based Lubricants by Trend Analysis UsingFourier Transform Infrared (FT-IR) SpectrometryD 7415 Test Method for Condition Monitoring of SulfateBy-Products in In-Service Petroleum and HydrocarbonBased Lubricants by Trend Analysis Using Fourier Trans-
20、form Infrared (FT-IR) SpectrometryD 7418 Practice for Set-Up and Operation of Fourier Trans-form Infrared (FT-IR) Spectrometers for In-Service OilCondition MonitoringE 131 Terminology Relating to Molecular SpectroscopyE 2412 Practice for Condition Monitoring of Used Lubri-cants by Trend Analysis Usi
21、ng Fourier Transform Infrared(FT-IR) Spectrometry3. Terminology3.1 DefinitionsFor definitions of terms relating to infraredspectroscopy used in this test method, refer to TerminologyE 131. For definitions of terms related to in-service oil condi-tion monitoring, refer to Practice D 7418.3.2 machiner
22、y health, nqualitative expression of the op-erational status of a machine subcomponent, 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.4. Summary
23、of Test Method4.1 This test method uses FT-IR spectrometry to monitoroxidation levels in in-service petroleum and hydrocarbon basedlubricants. The FT-IR spectra of in-service oil samples arecollected according to the protocol for either direct trendanalysis or differential trend analysis described i
24、n PracticeD 7418, and the levels of oxidation are measured using thepeak height or area measurements described herein.5. Significance and Use5.1 A large number of compounds, such as aldehydes,ketones, esters, and carboxylic acids, are produced when oilsreact with atmospheric oxygen. Oxidation is mea
25、sured using acommon FT-IR spectral feature between 1800 and 1670 cm-1caused by the absorption of the carbonyl group present in mostoxidation compounds. These oxidation products may lead toincreased viscosity (causing oil thickening problems), acidity(causing acidic corrosion), and formation of sludg
26、e and varnish(leading to filter plugging, fouling of critical oil clearances andvalve friction). Monitoring of oxidation products is thereforean important parameter in determining overall machineryhealth and should be considered in conjunction with data fromother tests such as atomic emission (AE) a
27、nd atomic absorption(AA) spectroscopy for wear metal analysis (Test MethodD 5185), physical property tests (Test Methods D 445 andD 6304), base reserve (Test Method D 2896 and D 4739), acidnumber tests (Test Methods D 664 and D 974) and other FT-IRoil analysis methods for nitration (Practice E 2412)
28、, sulfateby-products (Test Method D 7415), additive depletion (TestMethod D 7412), breakdown products and external contami-nants (Practice E 2412), which also assess elements of the oilscondition, see Refs (1-6).6. Interferences6.1 Various additive packages, especially those containingesters and car
29、boxylic acids, such as some viscosity indeximprovers, pour point depressants, and rust inhibitors, can givefalse positives for oxidation. In addition, oils mixed with anysynthetic ester based oil products will also give very highvalues for oxidation. One should trend the in-service oil againstthe ne
30、w oil to help identify these interferences. In some oils thecontributions from additive packages and synthetic ester basedoils may be so high that oxidation cannot be reliably measured.6.2 High levels of water contamination and soot will alsointerfere with the measurement of oxidation.7. Apparatus7.
31、1 Fourier transform infrared spectrometer equipped withsample cell, filter (optional) and pumping system (optional) asspecified in Practice D 7418.7.2 FT-IR Spectral Acquisition ParametersSet FT-IRspectral acquisition parameters according to instructions inPractice D 7418.8. Sampling8.1 Obtain a sam
32、ple of the in-service oil and a sample of thereference oil (required only for differential trend analysis)according to the protocol described in Practice D 7418.9. Preparation and Maintenance of Apparatus9.1 Rinse, flush, and clean the sample cell, inlet lines, andinlet filter according to instructi
33、ons in Practice D 7418.9.2 Monitor cell pathlength as specified in Practice D 7418.10. Procedure10.1 Collect a background spectrum according to the pro-cedure specified in Practice D 7418.10.2 Differential Trend Analysis OnlyCollect the absorp-tion spectrum of a reference oil sample according to the
34、procedure specified in Practice D 7418.10.3 Collect the absorption spectrum of an in-service oilsample according to the procedure specified in PracticeD 7418.10.4 Data ProcessingAll data are normalized to a path-length of 0.100 mm according to the procedure specified inPractice D 7418.11. Calculatio
35、n11.1 Calculation of Oxidation Value:D741409211.1.1 Procedure A (Direct Trend Analysis)Oxidation bythe direct trending method is calculated from the oil samplespectrum using the measurement area and baseline points listedin Table 1. Fig. 1 illustrates the area used in the measurementof oxidation in
36、the spectrum of diesel crankcase oil.11.1.2 Procedure B (Differential Trend Analysis)Oxidation by the differential trending method is calculatedfrom the differential spectrum using the measurement peak andbaseline points listed in Table 1. Fig. 2 illustrates the band usedin the measurement of oxidat
37、ion in the differential spectrum ofdiesel crankcase oil.11.2 Sample CarryoverTo ensure the minimum amount ofsample-to-sample cross-contamination or carryover, either aminimum volume of the subsequent sample or a solvent rinseshould be used to flush out the previous sample. The efficacy ofthe flushin
38、g protocol may be assessed by consecutively ana-lyzing an oil having a low (or zero) oxidation level (L1, forexample, a fresh oil) and a used oil sample having a highoxidation level (H1) followed by a second run of the oil samplehaving a low oxidation level (L2) and then calculating thepercent carry
39、over (PC) as follows. The calculated PC should beless than 5%.PC 5 L2L1!/H1 3 100 (1)where:L1, H1, and L2 = the values measured for oxidation (usingthe parameters given in Table 1) for thesamples run in the indicated sequence.12. Report12.1 Procedure A (Direct Trend Analysis)Values are re-ported in
40、units of absorbance/0.100 mm.12.2 Procedure B (Differential Trend Analysis)Values arereported in units of absorbance per centimeter (Abs/cm),calculated as follows:Oxidation in Abs/cm5 Oxidation in Abs/0.100 mm * 100 (2)12.3 TrendingData shall be recorded and reported atselected time intervals during
41、 the lubricants life. Ideally,oxidation values would be compared to that of the newlyformulated oil and plotted over time to visualize the relativechanges in oxidation and to determine when there needs to bean oil change, albeit other parameters may dictate this changeearlier. Sampling and reporting
42、 time intervals for oxidation arebased on the type of machinery and its previous historyassociated with this parameter.12.4 Statistical Analysis and Alarm LimitsFor statisticalanalysis and setting alarm limits, refer to Practice E 2412,Annex A3 on “Distribution Profiles and Statistical Analysis.”12.
43、5 Effects of Oil FormulationThe compositions of vari-ous oil formulations can have an effect on the results reportedfor oxidation value, and values from two different oil formu-lations should not be compared. Results should be interpretedrelative to values measured for unused oils of the sameformula
44、tion or trended directly from the sample history.13. Precision and Bias (Interim)413.1 PrecisionThe precision of the test method has notyet been determined by a formal interlaboratory study. Prelimi-nary examinations of repeatability have shown that the differ-ence between repetitive results obtaine
45、d by the same operatorin a given laboratory applying the same test method with thesame apparatus under constant operating conditions on identi-cal test material within short intervals of time would in the longrun, in the normal and correct operation of the test method,exceed the following values onl
46、y in one case in 20:repeatability = 0.68 absorbance units/0.100 mm forProcedure A (direct trend analysis)repeatability = 0.70 absorbance units/cm forProcedure B (differential trend analysis)The reproducibility of this test method is being determinedand will be available on or before May 1, 2013.13.2
47、 BiasThe procedures in this test method have no biasbecause the oxidation values can be defined only in the termsof the test method and no accepted reference method or valueis available.14. Keywords14.1 condition monitoring; differential trend analysis; directtrend analysis; Fourier transform infrar
48、ed; FT-IR; hydrocarbonbased lubricants; in-service petroleum lubricants; infrared; IR;lubricants; oils; oxidation4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D02-1668.TABLE 1 Parameters for Measuring Oxidation in In-ServiceP
49、etroleum and Hydrocarbon Based LubricantsMethod Measurement, cm Baseline Point(s), cm-1Procedure A(Direct Trend Analysis)Area from1800 to 1670Minima 2200 to 1900and 650 to 550Procedure B(Differential Trend Analysis)Maximum height from1800 to 1660Single point at 1950D7414093FIG. 1 Oxidation Measurement in the Spectrum of a Diesel Crankcase Oil for Direct Trend Analysis (Procedure A)FIG. 2 Oxidation Measurement in the Differential Spectrum of a Petroleum Crankcase Lubricant for Differential Trend Analysis(Procedure B)D7414094REFERENCES(1) Toms, L. A., and Toms, A
