1、Designation: D4898 16Standard 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 revision, the year of
2、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 U.S. Department of Defense.1. Scope*1.1 This test method covers the det
3、ermination of insolublecontamination in hydraulic fluids by gravimetric analysis. 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 0.45 m or 0
4、.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 units of me
5、asurement 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 regulatory l
6、imitations 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 PercentAlky-lben
7、zene Sulfonate Type (Withdrawn 2000)3E319 Practice for the Evaluation of Single-Pan MechanicalBalancesF302 Practice for Field Sampling of Aerospace Fluids inContainersF303 Practices for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 CountingPar
8、ticles from Aerospace Fluids on Membrane FiltersF314 Methods of Test for Identification of Metallic andFibrous Contaminants in Aerospace Fluids (Withdrawn1990)32.2 Military Standard:MIL-C-81302C Cleaning Compound Solvent Trichlorotrif-luoroethane43. Summary of Test Method3.1 The insoluble contaminat
9、ion is determined by passing agiven quantity of a fluid sample through a membrane filter diskand measuring the resultant increase in the mass 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, t
10、he filter disk is microscopically 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 flui
11、ds is essen-tial for the 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 m
12、ore than 0.005 mg during the test period. The ratedaccuracy shall be obtainable by personnel actually making the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.N0 on Hydraulic Flu
13、ids.Current edition approved Jan. 1, 2016. Published February 2016. Originallyapproved in 1965. Test Method F313 was redesignated as D4898 in 1988. Lastprevious edition approved in 2010 as D4898 90 (2010)1. DOI: 10.1520/D4898-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, o
14、rcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Standardization Documents Order
15、Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1weighings, under actual conditions of use a
16、nd 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 mm to 51 mmmembrane filters. The support shall be designed to enableattachment of a vacuum flask.5.3 Filtration Funnel, glass or stainless
17、 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, with rubber stopper.5.5 Filtered Liquid Dispensers (2)Washing bottles orother dispensers capable of
18、 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.55.7 Membrane Filters (2), 25 mm or 47 mm to 51 mm indiameter, with pore diameter as required.5.8 Microscope, capable of 35
19、 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 of80 C.5.11 Sample Bottles, with contamination-proof caps.Aluminum-foil wrapped stoppers or polyethylene liners be-tween ca
20、p 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 Weights, for microbalance, 10 mg and20 mg, accurate to 0.005 mg and made
21、from nonmagneticmaterial conforming to Type 310 in Specification A555/A555M. The accuracy is traceable to the National Bureau ofStandards as discussed in their Technical Note 288.6. Reagents6.1 Commercial Hexane, conforming to SpecificationsD1836.(WarningFlammable. Harmful if inhaled. Skin irri-tant
22、 on repeated contact. Eye irritant. Aspiration hazard.)6.2 Detergent, free-rinsing. Material conforming to Specifi-cation D2021.6.3 Isopropyl Alcohol, acetone-free. (WarningFlammable. Harmful if inhaled. Skin irritant on repeatedcontact. Eye irritant. Aspiration hazard.)6.4 Refrigerant-113 (trichlor
23、otrifluoroethane) conforming toU.S. Military Specification MIL-C-81302C. (WarningEnvironmentally hazardous substance. Harmful if inhaled.Skin irritant on repeated contact. Eye irritant. Aspirationhazard. Acute and chronic aquatic hazard.)7. Sample7.1 A 100 mL 6 1 mL fluid sample should be used for t
24、hismethod. 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 accordance with the
25、ir 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. Preparation of Apparatus8.1 The filtration funnel, petri dishes
26、, 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 (deliveredthrou
27、gh 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 irritant onre
28、peated 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 apparatus contaminat
29、ionfrom airborne dust. Use a protective hood or cover.NOTE 2One of the filters mentioned in 9.1 is for a blankdetermination, which is necessary to provide a correction factor foradsorption of hydraulic fluid by the filter, desorption of filter constituentsby the solvent, and variations of moisture c
30、ontent of the filter. This blankshould be determined for each sample of a given composition and history.In a series of samples of similar fluids with similar history, the blank needbe determined only once. However, with any change of sample volume, anew blank should be determined as the relationship
31、 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 sample container
32、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 Refrig-erant 113 f
33、rom a filtered liquid dispenser to rinse the residual5May be obtained from any source approved by U.S. Nuclear RegulatoryCommission.D4898 162sample 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
34、at the joint between the 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, ta
35、kingcare not to disturb the filter. With a fine steady stream, washany residual 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 was
36、hing until thetotal volume of filtered hexane equals 250 mL 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 80 C oven for 15 min.Other drying methods such as 5 min of continu
37、ous aspiratoraction or vacuum dessication may be substituted for theoven-drying method if such substituted method proves superiorto the oven method in achieving a constant mass uponcontinued drying. The nature of the contaminant will dictatethe drying method to be used.9.11 Allow the filters to equi
38、librate 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 Note 2). Remove static
39、 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 35. The presence of large orunusual particles or fibers shall be sufficient cause for request-
40、ing another sampling and analysis even though the allowablecontamination mass is not exceeded.9.14 For further examination of the filter, reference may bemade to Test Method F314.10. Calculations10.1 Calculate the mass of the contaminant as follows:10.1.1 Subtract the initial mass of the test filter
41、 (9.3) fromthe final mass (9.12) of the test filter (upper membrane).10.1.2 Subtract the initial mass of the blank filter from thefinal mass of the blank filter (lower membrane).10.1.3 Subtract the mass change of the blank filter from themass change of the test filter.10.1.4 The contamination mass i
42、s expressed as mg/100 mLof fluid sample retained on the specified pore diameter mem-brane 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 than3.6 % of the mass of contamination, measured as mg
43、/100 mLof the sample.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 determined.SUMMARY OF CHANGESSubcommittee D02.N0 has
44、identified the location of selected changes to this standard since the last issue(D4898 90 (2010)1) that may impact the use of this standard. (Approved Jan. 1, 2016.)(1) Revised subsections 1.1, 6.4, 7.1, 9.14, 10.1.1, and 10.1.2.(2) Revised Section 5.(3) Revised SI unit formatting throughout standa
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