1、Designation: D8127 17Standard 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 th
2、e 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 automatic wear particle analysis2test method forin-service lubricants describes u
3、sing 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 of suspended particulate of iron (Fe) andcopper (Cu) in such lubrica
4、nts.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 therange of 3.5 mg/kg to 92.4 mg/kg in the lubricant. Total particleco
5、unt 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) at any stage of degradation.1.4 This test method uses an empirical
6、 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 concerns, if any, associated with its use. It is theresponsibility of the
7、user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision
8、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:D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD5854 Practice for
9、 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 Guide for Statistically Evaluating Measurand AlarmLimits when Using Oil Analysis to M
10、onitor 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-Service Lubricant TestingE1621 Guide for Elemental Analysis by Wavelength Disper-s
11、ive 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 Definitions of Terms Specific to This Standard:3.1.1 contaminant particles, nparticles intr
12、oduced 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 with varying levels and amounts ofknown interferences. By diagonalizing the matrix o
13、f elementsand interferences, an equation for the inter-element correctionsfor each element of interest is obtained.1This 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
14、Analysis.Current edition approved July 1, 2017. Published August 2017. DOI: 10.1520/D8127-17.2Iron (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 analys
15、is method addresses common chal-lenges associated with extracting, counting, sizing, 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 100
16、36, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO 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
17、theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.3 filter active area, narea of the filter membranethrough which liquid is flowing.3.1.3.1 DiscussionAn example filter active area is 0.32squar
18、e 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 the plasticfeedthrough, against which the filter membrane is mounted, apiece of felt i
19、s 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 smooth disposablemembrane with circular pores of approximately 4 m incapture diameter.
20、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 manufacturingprocess yields an effective pore capture diameter of approxi-mately 4 m d
21、ue 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 theEDXRF spectrometry due to the formation of multiple layersof particulate on sample that
22、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 layers of the sample may affect the analysis.3.1.8 neat sample, na sample of in-service l
23、ubricantdrawn 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.3.1.10 syringing, vprocess by which a syringe is emptiedthrough a filter by way of applie
24、d 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, usually involvingprogressive loss or displacement of material, due to relativemotion be
25、tween 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 embedded various known amounts of metalpowders.3.1.13.1 DiscussionThis check standard
26、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 lubricants, probed forparticulate characteristics, and subsequently analyzed for el-eme
27、ntal 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 greater than 4 m.4.2 The EDXRF spectrometer provides the fluorescencespectrum, from whi
28、ch 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 correctionsmay also be applied.5. Significance and Use5.1 It has been shown in many industri
29、es 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 capture significant wear or even machinery failureevents. Such events are often accompanied
30、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 difficult to quantify. Users of the tech-nique include numerous military organizations,
31、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 theelements being monitored is present in significant amounts(500 mg/kg) in dissolved form in
32、 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 empirical correction factors), which are discussed in,for example, Test Method D7751,
33、 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 testmethod, but may nonetheless be present in the in-servicelubricant. Since the interrogated
34、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 quantitiesgreater than the range of calibration (500 mg/kg).6.3 Peculiar particle size distribution
35、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 when more small particles (4 m to 6 m in diameter)than the expected power law distributio
36、n are present by a factorof 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 largeD8127 172particle distribution. For example, the method has been testedto stay within specified c
37、alibration 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 particles(greater than 6 m in diameter) up to a factor of 6 relative tothe expected power la
38、w 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 membrane in place during the syringing process, as wellas ensuring that fluid flows thro
39、ugh 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 syringedthrough the filter. A typical setup shown in Fig. 2 containsassociated pressure mon
40、itoring 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 into the syringing apparatusparallel to the ground, again to prevent any captured part
41、iculate 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 lubricant is syringedthrough the filter membrane active area (x-axis of Fig. 3), suspende
42、dparticulate 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 amount oflubricant syringed can be directly related to the overall particle count inthe lub
43、ricant.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 blocked. Particle concentration limits arevalidated using appropriate concentrations of
44、 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 described in Test Method D7751, with a pro-grammable voltage tube, with a maximum tube
45、 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 window of the EDXRF, or any particulate captured on the filtermembrane from moving off t
46、he 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 obtained to provide calibration checks for theparticle count.8.2 Wax EDXRF calibration s
47、tandard is provided by themanufacturer. These are fabricated using consumer gradeFIG. 1 Disposable Filter CartridgeD8127 173paraffin canning wax as the base support material in thefollowing fashion: Warm 10 g to 20 g of the wax to nearmelting (50 C to 55 C), then add a small amount (0.5 mg) ofeach p
48、owdered 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 mixture byhand (using plastic gloves) until the metal powder is evenlydispersed throughout the
49、 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 with the warm waxstandard, pressing the wax in by hand. The excess wax may besliced off the top
