1、Designation: D8184 18Standard Test Method forFerrous Wear Debris Monitoring in In-Service Fluids Using aParticle Quantifier Instrument1This standard is issued under the fixed designation D8184; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 describes the use of offline particlequantification (often referred to as PQ)
3、magnetometers to trendwear rates in machinery by monitoring the amount of ferro-magnetic material suspended in a fluid sample that has been incontact with the moving parts of the machinery. It is particu-larly relevant to monitoring wear debris in lubricating oils andgreases.1.2 The values stated in
4、 SI units are to be regarded asstandard. Values of the burden (mass) of ferrous wear debris inthe sample are reported as a PQ Index. The PQ Index is anumerical value that scales with the ferrous debris burden.1.3 This standard does not purport to address all of thesafety concerns, if any, associated
5、 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.1.4 This international standard was developed in accor-dance with internationally recogniz
6、ed 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:2D4057 Practice for Manua
7、l Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum Products, LiquidFuels, and LubricantsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5185 Test Method for Multielement Determination ofUsed and Unused Lubricating Oils and Base Oils byInduct
8、ively Coupled Plasma Atomic Emission Spectrom-etry (ICP-AES)D6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD7720 Guide for Statistically Evaluating Measurand AlarmLimits when Using Oil Analysis to Monitor Equipmentand Oil for Fi
9、tness and Contamination3. Terminology3.1 Definitions:3.1.1 condition monitoring, nthe recording and analyzingof data relating to the condition of equipment or machinery forthe purpose of predictive maintenance or optimization ofperformance.3.1.2 ferromagnetic, nmetals, alloys, and other materialstha
10、t exhibit medium to high magnetic permeabilities; furtherclassified into “hard” and “soft” magnetic materials whencapable of becoming permanently magnetized or not, respec-tively.3.1.3 inductively coupled plasma optical emission spectros-copy (ICP-OES), na form of emission spectroscopy that usesa pl
11、asma to excite atoms and ions that subsequently emitelectromagnetic radiation in the visible region; the emissionwavelengths are characteristic of a particular wavelength, andthe intensity of emission is related to the concentration of theemitting element.3.1.4 machinery health, nqualitative indicat
12、ion of theoverall condition of equipment or machinery; may depend ondata and trend analysis from several sources.3.1.5 PQI, na dimensionless index related to the ferro-magnetic content of an oil or grease sample.3.1.5.1 DiscussionThe scale is defined by a 750 PQIprimary standard developed by The Uni
13、versity of Swansea inthe 1980s. The original primary standard is currently in thepossession of Parker Hannifin Manufacturing Ltd.(Littlehampton, UK) who manufacture and supply secondarystandards for instrument validation purposes.1This test method is under the jurisdiction of ASTM Committee D02 onPe
14、troleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.96.06 on Practices and Techniques for Prediction and Determi-nation of Microscopic Wear and Wear-related Properties.Current edition approved May 15, 2018. Published June 2018. DOI: 10.1520/D8184-18.2Fo
15、r 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 website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
16、, 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 the Wor
17、ld Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.6 rotating disc electrode optical emission spectroscopy(RDE-OES), nsimilar to ICP-OES, but the exciting mediumis now an electrical discharge between an electrode and arotating disc with the oil sample located within the discharge
18、.3.1.7 trend analysis, nthe interpretation of regular orcontinuous (in time) condition monitoring data in order todetermine any changes indicative of deterioration or incipientfailure in equipment or machinery.3.1.8 wear, nthe loss of material from a surface, generallyoccurring between two surfaces
19、in relative motion, and result-ing from mechanical or chemical action, or a combination ofboth.4. Summary of Test Method4.1 Lubricating OilsA sample of oil is extracted from themachinery and collected in a bottle to a depth sufficient toexceed the flux field of the sensing coil in the instrument.Dis
20、tortion of the flux field due to the presence of anyferromagnetic material is determined and a numerical value(PQ Index) assigned to the extent of the distortion. This indexis related to the concentration and spatial distribution of theferromagnetic material within the sensing volume of the coil. If
21、the oil sample has been undisturbed for some time, this is thesame as the concentration within the bulk. However, if theferrous burden undergoes settling, for example, from an initialwell-shaken state, then the signal may exhibit a time depen-dency due to debris mobility. It is possible to derive in
22、forma-tion on the size (mass) of the debris from the rate of any timedependent behavior noted.4.2 GreasesAsample of grease is similarly extracted froma bearing housing or similar and transferred to a small volume(5 mL) pot.3Reliable trending information requires the use ofthe same size and shape of
23、pot for reasons of consistency.Mobility of debris within grease is restricted, the contents ofthe pot are completely within the flux field of the sensing coil,and no time dependent behavior is observed.5. Significance and Use5.1 This test method is intended for the application of PQmagnetometry in a
24、ssessing the progression of wear inmachinery, for example, engines and gearboxes, by trendingthe mass of ferrous debris in samples of lubricating oils orgreases.5.2 In-service oil analysis is carried out routinely by com-mercial laboratories on a wide range of samples from manysources and is accepte
25、d as a reliable means of monitoringmachinery health by trend analysis. In particular, the extent ofwear can be readily assessed from any changes in the ferrousdebris burden within periodically extracted samples as re-flected in the PQ Index.5.3 PQ measurements can be used as a means of rapidlyscreen
26、ing samples for the presence or absence of ferrous weardebris, allowing quick decisions to be made on whether or notto proceed to a more detailed spectroscopic analysis forprobable wear metals in the sample.5.4 The use of standardized sample containers and a con-sistent protocol enables reliable tre
27、nding information to berecorded. Although it is not possible to assign general limits orthresholds for abnormal conditions, it is recommended thatinterpretation of PQ values should be carried out in consulta-tion with historical data, equipment logs, and/or service historyin order to formulate guide
28、lines on individual items of machin-ery. Guide D7720 is particularly useful in this context.6. Interferences6.1 Sample Related Interferences:6.1.1 PQ instruments have a high sensitivity to the presenceof low concentrations of ferromagnetic materials in the testmaterial (iron, steel, and so forth) du
29、e to their magneticsusceptibility. However, large concentrations of high conduc-tivity metals, for example, copper, can cause a small distortionto the excitation field through the generation of eddy currentsin the debris particles. These eddy currents generate anopposing ac magnetic field to the exc
30、itation field (Lenzs law),which causes an imbalance and hence a detectable signal. Notethat this phenomenon is several orders of magnitude lower ineffect than that due to the magnetic permeability of ferrousmaterials. The presence of any suspected high conductivitymetal contamination can be verified
31、 or eliminated by, forexample, Test Method D5185.6.2 External (Environmental) Interferences:6.2.1 As noted in 9.2, the toner material in some printedlabels can contain iron powder and care should be taken toeliminate this interference by careful label positioning and/orthe use of non-iron containing
32、 inks.6.2.2 PQ instruments should not be sited on or close to largemetallic structures due to the possibility of field distortioncaused by their proximity, see 10.1.7. Apparatus7.1 PQ instruments are of a propriety design and currentlymanufactured by Parker Hannifin Ltd., Littlehampton, U.K.4,5The d
33、evelopment of PQ test methodology began at SwanseaUniversity in the 1980s. Instruments have been manufacturedunder license, since the initial development, by Swansea OilAnalysis Program (SOAP) Ltd., Analex Ltd., and KittiwakeDevelopments Ltd, and a large number are still in operation inmany commerci
34、al laboratories. Current PQ instruments aremarketed and supported globally by Parker Hannifin Ltd.7.2 A description of the apparatus and method can be foundin the patents listed in Related Materials. In brief, PQ instru-ments comprise an excitation coil providing an ac magnetic3The sole source of su
35、pply of the apparatus (recommended grease sample pots)known to the committee at this time is Parker Hannifin Ltd., Littlehampton, UK. Ifyou are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameet
36、ing of the responsible technical committee,1which you may attend.4The sole source of supply of the apparatus known to the committee at this timeis Parker Hannifin Ltd., Littlehampton, U.K If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.You
37、r comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.5PQ GB trademark number 2210262 for “Apparatus and instruments for thedetection and/or quantification of wear debris in lubricating fluids and hydraulicfluids,” applies to the instr
38、ument and not the measurement index.D8184 182field with a frequency between 1 kHz and 10 kHz, two sensecoils arranged above and below the excitation coil and with thesample sited close to one of the excitation coils. See Fig. 1 andFig. 2 for details. In Fig. 2, 11 and 13 are the sample and asupport
39、plate, 2 is the excitation coil wound on a former (1), 3is an oscillator driving this coil, 4 and 5 are the two sense coilsarranged in a differential manner (initially balanced by somemeans to provide a null signal), with 6 through 8 providing ameans to detect and amplify any subsequent imbalance in
40、 thetwo sense coils from the presence of wear debris in the sample.9 is a display or recording device for this out-of-balance signal.7.3 To measure the ferrous burden in a sample in the formof the PQ index, the response of the instrument must becalibrated against the primary standard. This will have
41、 beendone by the manufacturer who will also supply secondarycheck standards to verify the long-term performance of theinstrument on an appropriate usage schedule. Consult themanual for guidance on this matter. Note that the sample platteralso contains an embedded ferrous reference for the purposesof
42、 compensating for any short-term drift.7.4 A full operational cycle consists of three measurements;zero PQI, embedded reference, and finally, the test sample.This is achieved by rotating the platter on which the sample isplaced in a stepwise fashion, pausing at each position to makethe appropriate m
43、easurement.8. Reagents and Materials8.1 No reagents are required in order to determine the PQIndex of a sample.8.2 It is recommended that PQ instruments are regularlycalibrated and their performance monitored using the manu-facturers recommendations and check standards.9. Sampling, Test Specimens, a
44、nd Test Units9.1 In-service oil and grease samples should be collected inaccordance with the practices described in Practice D4057 orPractice D4177. Oil samples should be transferred to clean100 mL bottles or 5 mL pots and sealed (Fig. 3). Greasesamples should be transferred to 5 mL pots and similar
45、lysealed. Suitable containers are available from several manu-facturers. For oil samples in 100 mL bottles, a minimum filldepth of 40 mm is recommended (Fig. 4). The 5 mL potsshould be completely filled with either oil or grease samples; aconsistent approach with respect to sample volume in this ste
46、pwill provide the most reliable results.9.2 Note that certain printer toners and inks can contain ironoxides. If it is required to attach printed labels to sample bottlesfor identification purposes, it is recommended that either thelabels are sited well away from the measurement zone or thatthe labe
47、ls be prepared using thermal type printers, in order toavoid erroneous measurements.9.3 Check standards are available from the manufacturer touse as test specimens for day to day validation and confidencechecking.10. Preparation of Apparatus10.1 PQ instruments are susceptible to variable temperature
48、effects and the presence of stray magnetic fields. They shouldbe sited in a stable, draft-free environment and kept well awayfrom any sources of electromagnetic interference, for example:power supplies, generators, microwave ovens, loudspeakers,and so forth. Note also that the close proximity of lar
49、ge steel oriron equipment may also disturb the measurement field and PQinstruments should not be sited near to gas cylinders or placedon steel workbenches.10.2 Sufficient time should be allowed for the instrument towarm up and equilibrate after first switch on. The manufactur-ers recommend waiting for a 2 h period before performingtests. It is anticipated that most PQ instruments will be left ina “permanently on/standby” state.10.3 In addition, cold sample bottles may affect the instru-ment when placed on the measurement platter, and they shouldalso be given sufficient
