1、Designation: D8127 171Standard Test Method forCoupled Particulate and Elemental Analysis using X-rayFluorescence (XRF) for In-Service Lubricants1This standard is issued under the fixed designation D8127; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he 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.1NOTEA heading in Table 3 was corrected editorially in April 2018.1. Scope1.1 This automatic wear
3、 particle analysis2test method forin-service lubricants describes using a combination of poreblockage particle counting and energy dispersive X-ray fluo-rescence (EDXRF) spectrometry for the quantitative determi-nation of solid particle counts larger than four (4) micrometres,and elemental content o
4、f suspended particulate of iron (Fe) andcopper (Cu) in such lubricants.1.2 This test method provides for the determination of theelemental content of suspended particulate of Fe greater than4 m in the range of 6 mg/kg to 223 mg/kg. Suspendedparticulate of copper greater than 4 m is determined in the
5、range of 3.5 mg/kg to 92.4 mg/kg in the lubricant. Total particlecount greater than 4 m is determined in the range of11 495 particles mL greater than 4 m to 2 169 500 parti-cles mL greater than 4 m in the lubricant.1.3 This test method is applicable to all known in-servicelubricants (API Groups I-V)
6、 at any stage of degradation.1.4 This test method uses an empirical inter-element correc-tion methodology.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 thesafety concern
7、s, 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 developed in accor-dance with int
8、ernationally 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.2. Referenced Documents2.1 ASTM Standards:D405
9、7 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD7669 Guide for Practical Lubricant Condition Data TrendAnalysisD7720 Gu
10、ide for Statistically Evaluating Measurand AlarmLimits when Using Oil Analysis to Monitor Equipmentand Oil for Fitness and ContaminationD7751 Test Method for Determination of Additive Elementsin Lubricating Oils by EDXRF AnalysisD7874 Guide for Applying Failure Mode and Effect Analy-sis (FMEA) to In
11、-Service Lubricant TestingE1621 Guide for Elemental Analysis by Wavelength Disper-sive X-Ray Fluorescence Spectrometry2.2 ISO Standards:3ISO 21018:3 Hydraulic fluid powerMonitoring the levelof particulate contamination of the fluidPart 3: Use ofthe filter blockage technique3. Terminology3.1 Definiti
12、ons of Terms Specific to This Standard:3.1.1 contaminant particles, nparticles introduced froman extraneous source into the lubricant of a machine or engine.3.1.2 empirical inter-element correction, nlinear inter-element correction that is constructed from a matrix of cali-bration samples prepared w
13、ith varying levels and amounts of1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved July 1, 2017. Published August 2017. DOI: 10.152
14、0/D8127-17E01.2Iron (Fe) and copper (Cu) alloy metals are common elements for machine loadbearing surfaces including bearings, gears, pistons, rings, valves, pins, couplings,and cylinders. This in-service lubricant analysis method addresses common chal-lenges associated with extracting, counting, si
15、zing, and elementally analyzingtelltale wear debris so that appropriate observations and actions may be recom-mended.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO
16、Box C700, West Conshohocken, PA 19428-2959. United StatesThis 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
17、 the World Trade Organization Technical Barriers to Trade (TBT) Committee.1known interferences. By diagonalizing the matrix of elementsand interferences, an equation for the inter-element correctionsfor each element of interest is obtained.3.1.3 filter active area, narea of the filter membranethroug
18、h which liquid is flowing.3.1.3.1 DiscussionAn example filter active area is 0.32square centimetre (cm2).3.1.4 filter cartridge, ndisposable assembly consisting ofa plastic filter holder, and the filter membrane itself mountedover a sealing plastic feedthrough.3.1.4.1 Discussion On the back side of
19、the plasticfeedthrough, against which the filter membrane is mounted, apiece of felt is mounted, through which the liquid exits thefilter cartridge. The felt is used to wick any remaining liquid offthe filter membrane once the syringing process is completed.3.1.5 filter membrane, na thin, flat, and
20、smooth disposablemembrane with circular pores of approximately 4 m incapture diameter.3.1.5.1 DiscussionAn example would be a polycarbonatetrack-etched membrane. There are approximately 32 000 ofsuch pores in the filter active area. Note that the nominal poresize is 5 m in diameter but the membrane
21、manufacturingprocess yields an effective pore capture diameter of approxi-mately 4 m due to observed edge material on the pores.3.1.6 interrogated material, nsolid material present on thefilter membrane that is analyzed by the EDXRF spectrometer.3.1.7 layering effect, ncomplex interferences to theED
22、XRF spectrometry due to the formation of multiple layersof particulate on sample that is being analyzed.3.1.7.1 DiscussionWhen multiple layers are present, inci-dent X-rays are attenuated as they travel through multiplelayers of the sample, and interferences between X-rays emerg-ing from various lay
23、ers of the sample may affect the analysis.3.1.8 neat sample, na sample of in-service lubricantdrawn directly from the machinery without further processing.3.1.9 suspended particulate, nparticles, includingcontaminant, wear, and soft particles, which can be trapped bya membrane filtration process.3.1
24、.10 syringing, vprocess by which a syringe is emptiedthrough a filter by way of applied force using a linear actuatoron its plunger.3.1.10.1 DiscussionThe filter is sealed to the syringe toensure that fluid passes from the syringe and through the filteronly.3.1.11 wear, ndamage to a solid surface, u
25、sually involvingprogressive loss or displacement of material, due to relativemotion between that surface and a contacting substance orsubstances.3.1.12 wear particles, nparticles generated from wearingsurfaces of a machine or engine.3.1.13 X-ray calibration standard, na paraffin wax puckin which is
26、embedded various known amounts of metalpowders.3.1.13.1 DiscussionThis check standard is placed in theEDXRF in order to provide a simple re-calibration of thedevice by the operator.4. Summary of Test Method4.1 This test method describes means by which particulatecan be trapped from neat in-service l
27、ubricants, probed forparticulate characteristics, and subsequently analyzed for el-emental content. This test method describes, from this process,means by which a total particle count in particles per millilitreof lubricant (particles/mL) may be obtained in accordance withISO 21018:3 for particles g
28、reater than 4 m.4.2 The EDXRF spectrometer provides the fluorescencespectrum, from which the elemental concentrations of iron andcopper are calculated using their respective fundamental Klines by way of the established calibration that includesinter-element corrections. Compton backscattering correc
29、tionsmay also be applied.5. Significance and Use5.1 It has been shown in many industries that separatinginformation regarding small or dissolved elemental materials inthe lubricant from suspended particulate is crucial. In manycases only an overall elemental analysis is provided, whichmay not captur
30、e significant wear or even machinery failureevents. Such events are often accompanied by a suddenincrease in the production of large particulate, which issuspended in and can be detected in the machinerys lubricant.This test method specifically targets such particulate, whichhas historically been di
31、fficult to quantify. Users of the tech-nique include numerous military organizations, and maintain-ers of wind turbines, nuclear power facilities, and offshore rigs.6. Interferences6.1 The filter presented for EDXRF analysis will have asmall amount of residual in-service lubricant. If any of theelem
32、ents being monitored is present in significant amounts(500 mg/kg) in dissolved form in the lubricant, the EDXRFwill see additional signal due to that dissolved elementalmaterial and report a positively biased signal for that element.6.2 Self-absorption, matrix, and inter-element effects (be-yond the
33、 empirical correction factors), which are discussed in,for example, Test Method D7751, are well-known and caninterfere with the reported quantities of each element. Further,no inter-element correction procedures have been developedfor interfering elements which are outside the scope of this testmeth
34、od, but may nonetheless be present in the in-servicelubricant. Since the interrogated material thickness is signifi-cantly smaller than the X-ray beam penetration and layeringeffects are small, these interfering effects are minimized, butwill still occur when any element is present in quantitiesgrea
35、ter than the range of calibration (500 mg/kg).6.3 Peculiar particle size distribution will affect the accu-racy of the particle count. Common particle size distributionsdemonstrate power law decay, where counts increasinglydecline as size increases. A high bias in particle count has beenobserved whe
36、n more small particles (4 m to 6 m in diameter)than the expected power law distribution are present by a factorD8127 1712of more than two. Similarly, when there are fewer smallparticles than expected by less than half, a low bias is expected.No bias has been observed when there is an abnormal largep
37、article distribution. For example, the method has been testedto stay within specified calibration up to a mass distribution ofsuspended particulate as a function of particle size which isapproximately flat from 4 m to 35 m. Such a distributionwould indicate an abnormally high presence of large parti
38、cles(greater than 6 m in diameter) up to a factor of 6 relative tothe expected power law distribution.7. Apparatus7.1 Asample processing system consisting of the following:7.1.1 A disposable filter cartridge functionally similar theone shown in Fig. 1, which serves the purpose of holding thefilter m
39、embrane in place during the syringing process, as wellas ensuring that fluid flows through the active area of the filtermembrane, out the back of the filter cartridge and a drain towaste.7.1.2 A syringing apparatus, into which the syringe andfilter cartridge are mounted and in-service lubricant syri
40、ngedthrough the filter. A typical setup shown in Fig. 2 containsassociated pressure monitoring sensors, linear actuator toperform the syringing, limit switches for the actuator, and drainto waste.NOTE 1The syringing apparatus is mounted perpendicular to theground, and the filter cartridge is mounted
41、 into the syringing apparatusparallel to the ground, again to prevent any captured particulate frombeing urged off or displaced from the filter active area. Fig. 3 provides afigurative example of a syringe dispensing profile characterizing poreblockage in the active area of the filter membrane.As lu
42、bricant is syringedthrough the filter membrane active area (x-axis of Fig. 3), suspendedparticulate will register as an increase in differential pressure (y-axis ofFig. 3) across the membrane, as the pores in the active area become filledwith this particulate. The pressure increase based on the amou
43、nt oflubricant syringed can be directly related to the overall particle count inthe lubricant.7.1.2.1 A predefined particle concentration limit is selectedand corresponds to a point on the dispensing profile at which apredefined percentage of pores in the active area of the filtermembrane have been
44、blocked. Particle concentration limits arevalidated using appropriate concentrations of standardized testdust in liquid medium such as the NIST (SRM 2806b) test duststandard or another well classified standard dust in liquidmedium.7.1.3 An energy-dispersive X-ray fluorescence spectrometer(EDXRF), as
45、 described in Test Method D7751, with a pro-grammable voltage tube, with a maximum tube voltage ratingsufficient to fluoresce the K lines of copper and iron.NOTE 2The EDXRF is preferably mounted with its sample interfacearea facing towards the ground. This prevents any liquid from drippinginto the w
46、indow of the EDXRF, or any particulate captured on the filtermembrane from moving off the filter active area. A typical arrangement isshown in Fig. 4.8. Reagents and Materials8.1 NIST (SRM 2806b) test dust standard or another appro-priate and well classified standard dust in liquid mediumshould be o
47、btained to provide calibration checks for theparticle count.FIG. 1 Disposable Filter CartridgeD8127 17138.2 Wax EDXRF calibration standard is provided by themanufacturer. These are fabricated using consumer gradeparaffin canning wax as the base support material in thefollowing fashion: Warm 10 g to
48、20 g of the wax to nearmelting (50 C to 55 C), then add a small amount (0.5 mg) ofeach powdered metal (average particle size 10 m, minimum99 % purity) of interest (examples are FE-M-02M-P10 UM foriron and CU-M-02M-P 10 UM for copper from AmericanElements, Los Angeles, CA). Knead the wax/metal mixtur
49、e byhand (using plastic gloves) until the metal powder is evenlydispersed throughout the wax. This usually requires severalcycles of re-warming the wax to soften it enough for effectivekneading. The original wax mixture is usually too concentratedin the metal powder, so must be diluted with up to tenfold cleanparaffin wax. After the metal powders are evenly dispersedthroughout the wax, a modified disposable filter cartridge isused to hold the final standard. A 6 cm hole is put in place ofthe filter membrane. This hole is filled wit
