1、Designation: D4898 90 (Reapproved 2010)Standard Test Method forInsoluble Contamination of Hydraulic Fluids by GravimetricAnalysis1This standard is issued under the fixed designation D4898; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method co
3、vers the determination of insolublecontamination in hydraulic fluids by gravimetric analyses. Thecontamination determined includes both particulate and gel-like matter, organic and inorganic, which is retained on amembrane filter disk of pore diameter as required by applicablespecifications (usually
4、 0.45 m or 0.80 m).1.2 To indicate the nature and distribution of the particulatecontamination, the gravimetric method should be supple-mented by occasional particle counts of typical samples inaccordance with Test Method F312.1.3 The values stated in SI units are to be regarded asstandard. No other
5、 units of measurement are included in thisstandard.1.4 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 standard to establish appro-priate safety and health practices and determine the applica-bility of
6、regulatory limitations prior to use. For a specificwarning statement, see 6.1.2. Referenced Documents2.1 ASTM Standards:2A555/A555M Specification for General Requirements forStainless Steel Wire and Wire RodsD1836 Specification for Commercial HexanesD2021 Specification for Neutral Detergent, 40 Perc
7、entAlkylbenzene Sulfonate TypeE319 Practice for the Evaluation of Single-Pan MechanicalBalancesF302 Practice for Field Sampling of Aerospace Fluids inContainersF303 Practices for Sampling for Particles in AerospaceFluids and ComponentsF312 Test Methods for Microscopical Sizing and CountingParticles
8、from Aerospace Fluids on Membrane FiltersF314 Test Methods for Identification of Metallic and Fi-brous Contaminants in Aerospace Fluids2.2 Military Standard:MIL-C-81302C Cleaning Compound Solvent Trichlorotrif-luoroethane33. Summary of Test Method3.1 The insoluble contamination is determined by pass
9、ing agiven quantity of a fluid sample through a membrane filter diskand measuring the resultant increase in the weight of the filter.The fluid sample is drawn through the filter by a vacuum andthe insoluble contamination is collected on the surface of thefilter. In addition, the filter disk is micro
10、scopically scanned forexcessively large particles, fibers, or other unusual conditions.4. Significance and Use4.1 This test method indicates and measures the amount ofinsoluble contamination of hydraulic fluids. Minimizing thelevels of insoluble contamination of hydraulic fluids is essen-tial for th
11、e satisfactory performance and long life of theequipment. Insoluble contamination can not only plug filtersbut can damage functional system components resulting inwear and eventual system failure.5. Apparatus5.1 Microbalance, accurate to 0.005 mg, and the zero shallnot drift more than 0.005 mg durin
12、g the test period. The ratedaccuracy shall be obtainable by personnel actually making theweighings, under actual conditions of use and shall be verifiedin accordance with Practice E319.5.2 Membrane Filter Support, fritted glass, sintered metal,or stainless steel screen, to support 25-mm or 47 to 51-
13、mm1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.N0.02 on Industrial Applications.Current edition approved Oct. 1, 2010. Published November 2010. Originallyapproved in 1965. Test Method F313 wa
14、s redesignated as D4898 in 1988. Lastprevious edition approved in 2005 as D489890(2005). DOI: 10.1520/D4898-90R10.2For 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 th
15、e standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-50981Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.membra
16、ne filters. The support shall be designed to enableattachment of a vacuum flask.5.3 Filtration Funnel, glass or stainless steel, minimumcapacity 15 mL, designed to enable attachment to the mem-brane filter support by means of a suitable clamping device.The filter funnel is calibrated to indicate vol
17、ume.5.4 Vacuum Flask, 250-mL, with rubber stopper.5.5 Filtered Liquid Dispensers (2)Washing bottles orother dispensers capable of delivering liquid through a 0.45-min-line membrane filter.5.6 Air Ionizer, alpha emitter, 18.5 MBq, of polonium-210,with a useful life of 1.5 years to a final value of 1.
18、1 MBq.45.7 Membrane Filters (2), 25 mm or 47 to 51 mm indiameter, with pore diameter as required.5.8 Microscope, capable of 353 magnification.5.9 Vacuum Source, capable of pulling 550 mm Hg. Anelectrically driven vacuum pump must be explosion-proof.5.10 Drying Oven, capable of maintaining a temperat
19、ure of80C.5.11 Sample Bottles, with contamination-proof caps.Aluminum-foil wrapped stoppers or polyethylene liners be-tween cap and bottle have proved satisfactory.5.12 Graduated Cylinder, 100-mL (May be replaced byvolume-calibrated filter funnel.)5.13 Petri Dishes, covered glass, 150 mm in diameter
20、.5.14 Forceps, with unserrated tips.5.15 Calibration Weights, for microbalance, 10 mg and 20mg, accurate to 0.005 mg and made from nonmagnetic materialconforming to Type 310 in Specification A555/A555M. Theaccuracy is traceable to the National Bureau of Standards asdiscussed in their Technical Note
21、288.6. Reagents6.1 Commercial Hexane, conforming to SpecificationsD1836.(WarningFlammable. Harmful if inhaled. Skin irri-tant on repeated contact. Eye irritant. Aspiration hazard.)6.2 Detergent, free-rinsing. Material conforming to Specifi-cation D2021.6.3 Isopropyl Alcohol, acetone-free. (WarningFl
22、ammable. Harmful if inhaled. Skin irritant on repeatedcontact. Eye irritant. Aspiration hazard.)6.4 Refrigerant-113 (trichlorotrifluoroethane) conforming toU.S. Military Specification MIL-C-81302C.(WarningFlammable. Harmful if inhaled. Skin irritant on repeatedcontact. Eye irritant. Aspiration hazar
23、d.)7. Sample7.1 A 100 6 1-mL fluid sample shall be used for thismethod. Larger or smaller samples may be used, however, tomeet problems of unusually high or low contamination levels.NOTE 1Methods for obtaining the fluid samples are not specified inthis method. These methods should be established by
24、the individualagencies or laboratories in accordance with their requirements. However,extreme care should be taken to ensure that the samples are representativeand free of external contamination.7.2 The following ASTM sampling test methods should beused when applicable: Practices F302 and F303.8. Pr
25、eparation of Apparatus8.1 The filtration funnel, petri dishes, graduated cylinders,and sample bottles shall be cleaned before each use by thefollowing method:8.1.1 Thoroughly wash in a solution of detergent and hotwater.8.1.2 Rinse with hot tap water and finally with distilled ordeionized water.8.1.
26、3 Rinse twice with filtered isopropyl alcohol (deliveredthrough a filtered liquid dispenser).8.1.4 Rinse twice with filtered commercial hexane (deliv-ered through filtered liquid dispenser).8.1.5 Leave approximately 1 mL of commercial hexane inthe bottom of each sample bottle. Replace sample bottle
27、cap.(WarningFlammable. Harmful if inhaled. Skin irritant onrepeated contact. Eye irritant. Aspiration hazard.)9. Procedure9.1 Select two membrane filters of the pore diameter re-quired. Allow the filters to stabilize to equilibrium withambient room conditions. Record room temperature and rela-tive h
28、umidity.9.2 Take precautions to minimize apparatus contaminationfrom airborne dust. Use a protective hood or cover.NOTE 2One of the filters mentioned in 9.1 is for a blank determina-tion, which is necessary to provide a correction factor for adsorption ofhydraulic fluid by the filter, desorption of
29、filter constituents by the solvent,and variations of moisture content of the filter. This blank should bedetermined for each sample of a given composition and history. In a seriesof samples of similar fluids with similar history, the blank need bedetermined only once. However, with any change of sam
30、ple volume, anew blank should be determined as the relationship of blank correction tosample volume cannot be extrapolated.9.3 Using forceps, weigh each filter on a microbalance tothe nearest 0.005 mg.9.4 Place the filters, one above the other, in the filtrationapparatus. Ground the clamp to reduce
31、static buildup duringfiltration.9.5 Shake the sample container for approximately 1 min.9.6 Measure the desired sample volume with a graduatedcylinder and pour into the filter funnel, or pour the requiredvolume directly into a calibrated filter funnel. Apply a vacuumand filter the entire sample.9.7 U
32、se a stream of filtered commercial hexane or Refrig-erant 113 from a filtered liquid dispenser to rinse the residualsample from the graduated cylinder into the filter funnel and towash down the inside of the filter funnel. The outside of thefilter unit should also be washed at the joint between the
33、filterholder and filter base to remove fluid between the holder andthe filter disk. Repeat the washing twice so that a total ofapproximately 100 mL of commercial hexane or Refrigerant113 is used for the washing process.9.8 With the vacuum still applied, remove the funnel, takingcare not to disturb t
34、he filter. With a fine steady stream, washany residual hydraulic fluid from the periphery of the filter withfiltered commercial hexane. The washing action should be4May be obtained from any source approved by U.S. Nuclear RegulatoryCommission.D4898 90 (2010)2towards the center with care taken not to
35、 disturb the depositedcontaminates on the filter surface. Continue washing until thetotal volume of filtered hexane equals 250 to 300 mL.9.9 Dry the filters with aspirator action and release thevacuum.9.10 Using forceps, remove the filters and place in a coveredpetri dish. Place the petri dish in an
36、 80C oven for 15 min.Other drying methods such as 5 min of continuous aspiratoraction or vacuum dessication may be substituted for theoven-drying method if such substituted method proves superiorto the oven method in achieving a constant weight uponcontinued drying. The nature of the contaminant wil
37、l dictatethe drying method to be used.9.11 Allow the filters to equilibrate to ambient room condi-tions for 5 min in the petri dish with cover ajar. Record theroom temperature and relative humidity. When these valuesdiffer from ambient conditions recorded as described in 9.1,results will be invalid
38、unless a blank filter is run concurrently(see Note 2). Remove static electricity by placing each mem-brane on the air ionizer for several seconds.9.12 Weigh each filter to the nearest 0.005 mg.9.13 Inspect the same filter (upper membrane) under amicroscope at approximately 353. The presence of large
39、 orunusual particles or fibers shall be sufficient cause for request-ing another sampling and analysis even though the allowablecontamination weight is not exceeded.9.14 For further examination of the filter, reference may bemade to Test Method F314.(WarningFlammable. Harmfulif inhaled. Skin irritan
40、t on repeated contact. Eye irritant.Aspiration hazard.)10. Calculations10.1 Calculate the weight of the contaminant as follows:10.1.1 Subtract the initial weight (9.3) from the final weight(9.12) of the test filter (upper membrane) and of the blank filter(lower membrane).10.1.2 Subtract the weight c
41、hange of the blank from theweight change of the test filter.10.1.3 The contamination weight is expressed asmilligrams/100 mL of fluid sample retained on the specifiedpore diameter membrane filter.11. Precision and Bias11.1 Precision:11.1.1 RepeatabilityDuplicate results by the same opera-tor should
42、be considered suspect if they differ by more than3.6 % of the weight of contamination per 100 mL of thesample.11.1.2 ReproducibilityAvailable data do not justify anystatement.11.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure for measur-ing inso
43、luble contamination, no bias can be determined.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights,
44、and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revi
45、sion of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you
46、shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4898 90 (2010)3
