1、Designation: D 4898 90 (Reapproved 2005)An American National StandardStandard Test Method forInsoluble Contamination of Hydraulic Fluids by GravimetricAnalysis1This standard is issued under the fixed designation D 4898; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense
3、.1. Scope1.1 This test method covers 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 a
4、pplicablespecifications (usually 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 F 312.1.3 The values stated in SI units are to
5、 be regarded as thestandard.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 regulatory limitations
6、prior to use. For a specificwarning statement, see 6.1.2. Referenced Documents2.1 ASTM Standards:2A 555/A 555M Specification for General Requirements forStainless Steel Wire and Wire RodsD 1836 Specification for Commercial HexanesD 2021 Specification for Neutral Detergent, 40 PercentAlkylbenzene Sul
7、fonate TypeE 319 Practice for the Evaluation of Single-Pan MechanicalBalancesF 302 Practice for Field Sampling of Aerospace Fluids inContainersF 303 Practices for Sampling Aerospace Fluids from Com-ponentsF 312 Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membrane
8、FiltersF 314 Test Methods for Identification of Metallic and Fi-brous Contaminants in Aerospace Fluids2.2 Military Standard:MIL-C-81302 C Cleaning Compound Solvent Trichlorotri-fluoroethane33. Summary of Test Method3.1 The insoluble contamination is determined by passing agiven quantity of a fluid s
9、ample 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 microscopically scanned forexcessivel
10、y 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 the satisfactory performance and l
11、ong 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 during the test period. The ratedaccu
12、racy shall be obtainable by personnel actually making theweighings, under actual conditions of use and shall be verifiedin accordance with Practice E 319.5.2 Membrane Filter Support, fritted glass, sintered metal,or stainless steel screen, to support 25-mm or 47 to 51-mmmembrane filters. The support
13、 shall be designed to enableattachment of a vacuum flask.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum and Petroleum Products and is the direct responsibility of SubcommitteeD02.N0 on Hydraulic Fluids.Current edition approved May 1, 2005. Published May 2005. Originall
14、yapproved in 1965. Test Method F 313 70 was redesignated D 4898 73 (1983)e1in 1988. Last previous edition approved in 2000 as D 4898 90 (2000)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
15、volume information, refer to the 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 1
16、9428-2959, United States.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 volume.5.4 Vacuum Flask, 250-mL, with rubber stopper.5.5 F
17、iltered 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 1.1 MBq.45.7 Membrane Filters (2), 25 mm or 47 to 51 mm i
18、ndiameter, 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 temperature of80C.5.11 Sample Bottles, with contamination-proof
19、 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.5.14 Forceps, with unserrated tips.5.15 Calibration We
20、ights, for microbalance, 10 mg and 20mg, accurate to 0.005 mg and made from nonmagnetic materialconforming to Type 310 in Specification A 555/A 555M. Theaccuracy is traceable to the National Bureau of Standards asdiscussed in their Technical Note 288 .6. Reagents6.1 Commercial Hexane, conforming to
21、SpecificationsD 1836 (WarningFlammable. Harmful if inhaled. Skin irri-tant on repeated contact. Eye irritant. Aspiration hazard.).6.2 Detergent, free-rinsing. Material conforming to Specifi-cation D 2021.6.3 Isopropyl Alcohol, acetone-free (WarningFlammable. Harmful if inhaled. Skin irritant on repe
22、atedcontact. 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 hazard.).7. Sample7.1 A 100 6 1-mL fluid sample shall b
23、e 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 the individualagencies or laboratories in accorda
24、nce 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 F 302 and F 303.8. Preparation of Apparatus8.1 The filtration funnel
25、, 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.8.1.3 Rinse twice with filtered isopropyl alcohol (
26、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 cap(WarningFlammable. Harmful if inhaled. Skin
27、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 humidity.9.2 Take precautions to minimize appara
28、tus 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 filter constituents by the solvent,and variatio
29、ns 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 sample volume, anew blank should be determined as
30、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 static buildup duringfiltration.9.5 Shake the s
31、ample 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 Use a stream of filtered commercial hexane or Re
32、frig-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 filterholder and filter base to remove fluid be
33、tween 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 the filter. With a fine steady stream, washany r
34、esidual hydraulic fluid from the periphery of the filter withfiltered commercial hexane. The washing action should betowards the center with care taken not to disturb the depositedcontaminates on the filter surface. Continue washing until thetotal volume of filtered hexane equals 250 to 300 mL.4May
35、be obtained from any source approved by U.S. Nuclear RegulatoryCommission.D 4898 90 (2005)29.9 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 80C oven for 15 min.Other drying methods such
36、 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 will dictatethe drying method to be used.9.11 All
37、ow 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 unless a blank filter is run concurrently(see
38、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 orunusual particles or fibers shall be suffic
39、ient 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 F 314 (WarningFlammable. Harmfulif inhaled. Skin irritant on repeated contact. Eye irritant.Aspiratio
40、n 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 change of the blank from theweight change of
41、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 be considered suspect if they differ by more
42、 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 insoluble contamination, no bias can be determin
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44、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 revision of this standard or for additional stan
45、dardsand 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 shouldmake your views known to the ASTM Comm
46、ittee 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).D 4898 90 (2005)3
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