1、Designation: D 7415 09Standard Test Method forCondition Monitoring of Sulfate By-Products in In-ServicePetroleum and Hydrocarbon Based Lubricants by TrendAnalysis Using Fourier Transform Infrared (FT-IR)Spectrometry1This standard is issued under the fixed designation D 7415; the number immediately f
2、ollowing 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 met
3、hod covers monitoring sulfate by-productsin in-service petroleum and hydrocarbon based diesel crank-case engine and motor oils that have a sulfur content of greaterthan 500 ppm. This test method should not be employed whenlow-sulfur fuels are used for combustion.1.2 This test method uses Fourier Tra
4、nsform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubri-cants as a result of normal machinery operation. Sulfateby-products can result from the introduction of sulfur fromcombustion or from the oxidation of sulfur-contai
5、ning base oiladditives. This test method is designed as a fast, simplespectroscopic check for monitoring of sulfate by-products inin-service petroleum and hydrocarbon based lubricants withthe objective of helping diagnose the operational condition ofthe machine based on measuring the level of sulfat
6、e by-products in the oil.1.3 Acquisition of FT-IR spectral data for measuring sulfateby-products in in-service oil and lubricant samples is describedin Practice D 7418. In this test method, measurement and datainterpretation parameters for sulfate by-products using bothdirect trend analysis and diff
7、erential (spectral subtraction) trendanalysis are presented.1.4 This test method is based on trending of spectralchanges associated with sulfate by-products of in-servicepetroleum and hydrocarbon based lubricants. Warnings oralarm limits can be set on the basis of a fixed minimum valuefor a single m
8、easurement or, alternatively, can be based on arate 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 recorde
9、dfrom 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-timetre).1.4.3 In either case, maintenance action lim
10、its should bedetermined through statistical analysis, history of the same orsimilar equipment, round robin tests or other methods inconjunction with the correlation of sulfate by-product changesto equipment performance.NOTE 1It is not the intent of this test method to establish orrecommend normal, c
11、autionary, 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,includi
12、ng 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, associate
13、d 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:3D 445 Test Method for Kinematic Viscosity of Transparentand Op
14、aque Liquids (and Calculation of Dynamic Viscos-ity)D 974 Test Method for Acid and Base Number by Color-Indicator Titration1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.96 on In-Service Lubric
15、ant Testing and Condition Monitoring Services.Current edition approved July 1, 2009. Published August 2009.2The boldface numbers in parentheses 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 Servi
16、ce 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 Conshohocken, PA 19428-2959, United States.D 2896 Test Method for Base Number of Petrole
17、um Prod-ucts by Potentiometric Perchloric Acid TitrationD 4739 Test Method for Base Number Determination byPotentiometric Hydrochloric Acid TitrationD 5185 Test Method for Determination of Additive Ele-ments, Wear Metals, and Contaminants in Used Lubricat-ing Oils and Determination of Selected Eleme
18、nts 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 Antiwear Additives
19、in In-Service Petroleum andHydrocarbon Based Lubricants by Trend Analysis UsingFourier Transform Infrared (FT-IR) SpectrometryD 7414 Test Method for Condition Monitoring of Oxidationin In-Service Petroleum and Hydrocarbon Based Lubri-cants by Trend Analysis Using Fourier Transform Infrared(FT-IR) Sp
20、ectrometryD 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 Using Fourier Transform Inf
21、rared(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 machinery health, nqualitative e
22、xpression 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 of Test Method4.1 This t
23、est method uses FT-IR spectrometry to monitorsulfate by-product in in-service petroleum and hydrocarbonbased lubricants. The FT-IR spectra of in-service oil samplesare collected according to the protocol for either direct trendanalysis or differential trend analysis described in PracticeD 7418, and
24、the levels of sulfate by-products are measuredusing the peak height or area measurements described herein.5. Significance and Use5.1 An increase in sulfate material can be an indicator of oildegradation caused by oxidation of sulfur in the oil and sulfurin fuel. It can also indicate the breakdown or
25、 oxidation of somekey additives in the oil such as antiwear and extreme pressureadditives as well as blow-by concerns. As oxidized sulfur fromblow-by enters the lubricant, it will consume the overbaseadditive to generate sulfate by-products. Monitoring of sulfateby-products is therefore an important
26、 parameter in determiningoverall machinery health and in determining additive depletionand should be considered in conjunction with data from othertests such as atomic emission (AE) and atomic absorption (AA)spectroscopy for wear metal analysis (Test Method D 5185),physical property tests (Test Meth
27、ods D 445, D 2896, andD 6304), base number tests (Test Methods D 974 and D 4739)and other FT-IR oil analysis methods for nitration (PracticeE 2412), oxidation (Test Method D 7414), additive depletion(Test Method D 7412), breakdown products and external con-taminants (Practice E 2412), which also ass
28、ess elements of theoils condition, see Refs (1-6)6. Interferences6.1 Various additive packages, especially those containingdetergents, dispersants, demulsifiers and overbase additives,will interfere with the sulfate by-products measurement.6.2 Contaminants such as esters, polyols, glycols and alco-h
29、ols will also interfere with the measurement of sulfateby-products.6.3 Oxidation by-products can be a major source of inter-ference in the measurement of sulfate by-products. Because ofthis interference, the low levels of sulfate by-products associ-ated with the use of low-sulfur fuels for combustio
30、n cannot beadequately measured.7. Apparatus7.1 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
31、inPractice D 7418.8. Sampling8.1 Obtain a sample 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
32、lines, andinlet filter according to instructions 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 spectr
33、um of a reference oil sample according to theprocedure 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 procedu
34、re specified inPractice D 7418.11. Calculation11.1 Calculation of Sulfate By-Products Value:D741509211.1.1 Procedure A (Direct Trend Analysis)Sulfate by-products value by the direct trending method is calculated fromthe oil sample spectrum using the measurement area andbaseline points listed in Tabl
35、e 1. Fig. 1 illustrates the area usedin the measurement of sulfate by-products in the spectrum ofdiesel crankcase oil.11.1.2 Procedure B (Differential Trend Analysis)Sulfateby-products value by the differential trending method iscalculated from the differential spectrum using the measure-ment peak a
36、nd baseline points listed in Table 1. Fig. 2illustrates the band used in the measurement of sulfate by-products in the differential spectrum of diesel crankcase oil.11.2 Sample CarryoverTo ensure the minimum amount ofsample-to-sample cross-contamination or carryover, either aminimum volume of the su
37、bsequent sample or a solvent rinseshould be used to flush out the previous sample. The efficacy ofthe flushing protocol may be assessed by consecutively ana-lyzing an oil having a low (or zero) sulfate by-product level(L1, for example, a fresh oil) and a used oil sample having ahigh sulfate by-produ
38、ct level (H1) followed by a second run ofthe oil sample having a low sulfate by-product level (L2) andthen calculating the percent carryover (PC) as follows Thecalculated PC should be less than 5%.PC 5 L2L1!/H1 3100 (1)where:L1, H1, and L2 = the values measured for sulfate by-products (using the par
39、ameters given inTable 1) for the samples run in theindicated sequence.12. Report12.1 Procedure A (Direct Trend Analysis)Values are re-ported in 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 f
40、ollows:Sulfate By-Products in Abs/cm= Sulfate By-Products in Abs/0.100 mm * 10012.3 TrendingData shall be recorded and reported atselected time intervals during the lubricants life. Ideally,sulfate by-products values would be compared to that of thenewly formulated oil and plotted over time to visua
41、lize therelative changes in sulfate by-products and to determine whenthere needs to be an oil change, albeit other parameters maydictate this change earlier. Sampling and reporting time inter-vals for sulfate by-products are based on the type of machineryand its previous history associated with this
42、 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.”12.5 Effects of Oil FormulationThe compositions of vari-ous oil formulations can have an effect on the results
43、reportedfor sulfate by-products value, and values from two different oilformulations should not be compared. Results should beinterpreted relative to values measured for unused oils of thesame formulation or trended directly from the sample history.13. Precision and Bias (Interim)413.1 PrecisionThe
44、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 obtained by the same operatorin a given laboratory applying the same test method with thesame apparatus und
45、er 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 only in one case in 20:repeatability = 0.30 absorbance units/0.100 mm forProcedure A (direct trend anal
46、ysis)repeatability = 0.31 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 BiasThe procedures in this test method have no biasbecause the sulfate by-products values can be de
47、fined only inthe terms of the test method and no accepted reference methodor value is available.14. Keywords14.1 condition monitoring; differential trend analysis; directtrend analysis; Fourier transform infrared; FT-IR; hydrocarbonbased lubricants; in-service petroleum lubricants; infrared; IR;lubr
48、icants; oils; sulfate by-products4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D02-1669.TABLE 1 Parameters for Measuring Sulfate By-Products in In-Service Petroleum and Hydrocarbon Based LubricantsMethod Measurement, cm-1Base
49、line Point(s), cm-1Procedure A(Direct Trend Analysis)Area from1180 to 1120Minima 2200 to 1900and 650 to 550Procedure B(Differential Trend Analysis)Height at 1150 Single point at 1950D7415093FIG. 1 Sulfate By-Products Measurement in the Spectrum of a Diesel Crankcase Oil for Direct Trend Analysis (Procedure A)FIG. 2 Sulfate By-Products Measurement in the Differential Spectrum of a Petroleum Crankcase Lubricant for Differential TrendAnalysis (Procedure B)D7415094REFERENCES(1) Toms, L. A., and Toms, A. M., Machinery Oil Analysis: Methods,Automation or through the
