1、Designation: F 311 08Standard Practice forProcessing Aerospace Liquid Samples for ParticulateContamination Analysis Using Membrane Filters1This standard is issued under the fixed designation F 311; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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 practice covers the processing of liquids in prepa-ration for particulate contaminatio
3、n analysis using membranefilters and is limited only by the liquid-to-membrane filtercompatibility.1.2 The practice covers the procedure for filtering a mea-sured volume of liquid through a membrane filter. When thispractice is used, the particulate matter will be randomlydistributed on the filter s
4、urface for subsequent contaminationanalysis methods.1.3 The practice describes procedures to allow handlingparticles in the size range between 2 and 1000 m withminimum losses during handling.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included i
5、n thisstandard.2. Referenced Documents2.1 ASTM Standards:2D 287 Test Method forAPI Gravity of Crude Petroleum andPetroleum Products (Hydrometer Method)D 1078 Test Method for Distillation Range of VolatileOrganic LiquidsD 1193 Specification for Reagent WaterD 1353 Test Method for Nonvolatile Matter i
6、n VolatileSolvents for Use in Paint, Varnish, Lacquer, and RelatedProductsD 1836 Specification for Commercial HexanesD 2021 Specification for Neutral Detergent, 40 PercentAlkylbenzene Sulfonate Type3F 302 Practice for Field Sampling of Aerospace Fluids inContainersF 303 Practices for Sampling for Pa
7、rticles in AerospaceFluids and ComponentsF 312 Test Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membrane Filters3. Terminology Definition3.1 filtered liquid dispenseras used in this practice, adispenser capable of delivering rinse liquid through a filter withpore
8、size no larger than half the size of the smallest particlebeing considered for measurement.4. Significance and Use4.1 This practice provides for the processing of liquidsamples obtained in accordance with Practice F 302 andPractices F 303. It will provide the optimum sample processingfor visual cont
9、amination methods such as Method F 312, andTest Method F 314.5. Apparatus and Materials5.1 Filtration FunnelThe funnel opening in contact withthe membrane shall be approximately 35.0 mm in insidediameter. The effective area shall be calibrated. If the funnel isto be used for measuring the sample vol
10、ume, the funnel shallbe calibrated within 62 % of the required volume.5.2 Membrane Filter SupportEither a fritted-glass,sintered-metal, polyphenyl-sulfone or stainless steel screenmay be used. The support shall be so designed as to enableattachment to a vacuum flask.5.3 Vacuum Flask.5.4 Funnel-Holdi
11、ng DeviceA provision should be madefor the dissipation of static electricity from the funnel.1This practice is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition
12、approved May 1, 2008. Published May 2008. Originallyapproved in 1969. Last previous edition approved in 2002 as F 311 97 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
13、n, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.5 A clean bench or hood, supplied with unidirectionalflow filtered air, in which uncovered components may
14、 beplaced.5.6 Vacuum SourceMinimum vacuum gage reading of 61kPa (or other metric units acceptable to ASTM).5.7 Forceps, unserrated tips.5.8 Filtered Liquid Dispenser.5.9 Membrane Filter, pore size no greater than half the sizeof the smallest particle being considered for measurement. Thefilter shall
15、 have an imprinted grid on 3.10 6 0.02-mm centers.The color shall be chosen to provide maximum contrast withthe particulate contamination to be observed.NOTE 1When testing military hydraulic fluids, a white cellulosemembrane of 0.45-m pore size, capable of filtering 80 mL of distilledwater per squar
16、e centimeter per minute at 93 kPa (or other metric unitsacceptable to ASTM) and 25C is required.5.10 Petri Dishes, glass. Plastic Petri dishes may be usedonly if the selected plastic is known to be compatible with thefiltered liquid.5.11 Glass Bottles, small-mouth, screw-capped, perma-nently marked
17、to indicate sample volume.5.12 Plastic Film, 0.002-in. (0.05-mm) minimum thickness.5.13 Contrasting Pigment Suspension, to be used in calibra-tion of the funnel.5.14 Slides, glass, 50 by 50-mm.5.15 Tape, transparent, pressure-sensitive.6. Reagents and Materials6.1 Purity of ReagentsReagent grade che
18、micals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertain
19、ed that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193, Type III or clearer.6.3 Detergent, fre
20、e-rinsing. Material conforming to Specifi-cation D 2021 is suitable.6.4 Isopropyl Alcohol, acetone-free.56.5 Solvent, conforming to the following requirements(Note 2):6.5.1 Distillation Range, initial boiling point 27C (80F)min; dry point 71C (160F) max, as determined in accordancewith Test Method D
21、 1078.6.5.2 API Gravity, 70 deg min, as determined in accordancewith Test Method D 287.6.5.3 Residue, 0.004 g/100 mL max, as determined inaccordance with Method D 1353.NOTE 2Commercial hexanes conforming to Specification D 1836meet this requirement. Other chlorinated solvents, conforming to theMontr
22、eal conference on control of chlorinated fluorocarbons may besubstituted where solvent presents a safety hazard, providing the substitutesolvent is compatible with the membrane filter and adequate ventilation isused to avoid inhalation of the vapors.6.6 Rinse LiquidThis liquid shall be specified by
23、the userand shall be compatible with the sample liquid the plastic film(see section 5.12) and the membrane filter.7. Preparation of Apparatus7.1 Wash the apparatus thoroughly in a solution of liquiddetergent and hot water and rinse with hot tap water (Note 3).Rinse with filtered isopropyl alcohol to
24、 remove the water; thenrinse twice with filtered solvent.NOTE 3Distilled or deionized water shall be used in areas wherehardness or contamination increase the blank count over the allowablelevel.7.2 Sample Bottle PreparationRepeat the procedure of7.1 for both the sample bottles and caps, then allow
25、them todrip dry. Place a piece of plastic film that has been rinsed withfiltered liquid over the mouth of the bottle. Hold the film whilescrewing on the cap to prevent the film from rotating.NOTE 4It is important to hold the film when applying and removingthe cap to prevent serration.8. Funnel Calib
26、ration8.1 Disperse a small quantity of pigment into 100 mL ofliquid in a glass bottle. Prepare for a filtration as described in9.1. Filter the suspension through the membrane filter andallow to dry. Release the vacuum and remove the membranefilter. Place the membrane on a flat surface and measure th
27、epigment stain at three diameters 0, 45 and 90, with a verniercaliper to the nearest 0.1 mm.8.2 Average the three measurements and calculate the areaas follows:Area 5pD2/4 (1)8.3 Mark the funnel to allow identification with calculatedarea. Rinse the filter funnel three times with clean liquid toremo
28、ve remaining pigment from the funnel surface.9. Procedure9.1 Blank Analysis Filtration:9.1.1 Remove a membrane from the container and rinsewith filtered liquid. Place the membrane on the support, lowerthe funnel, and secure with the holding device. Cover thefunnel.9.1.2 Place an amount of filtered l
29、iquid equal to the amountof fluid used in the routine sample filtration in a sample bottleand agitate. Remove the cover and pour the contents of thebottle into the funnel. Place approximately 50 mL of rinseliquid into the bottle and agitate. Pour rinse liquid into thefunnel and cover.9.1.3 Turn on t
30、he vacuum and allow the liquid to filter untilapproximately one third remains. Lift the cover and carefullywash down the funnel walls with rinse liquid (Note 5). Replacethe cover and filter until the membrane is dry. Remove theholding device and funnel (see Note 6 and Note 7), then turn4“Reagent Che
31、micals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of reagents not listed bytheAmerican Chemical Society, see “Reagent Chemicals and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacop
32、eia.”5Material conforming to USP XVII, 1965, p. 995 is suitable.F311082off the vacuum immediately. Remove the membrane using theforceps and place it in a petri dish labeled “Blank.” The usermay choose to subtract the blank from his sample counts, ormay establish a maximum standard for particles in t
33、he blank.NOTE 5When the fluid filtration rate is excessive, the vacuum shouldbe released to allow adequate rinsing of the funnel walls.NOTE 6Do not slide the funnel during this operation.NOTE 7When filtration is completed the rate of repressurization shallbe such that no fluid agitation shall occur
34、which could re-wet the filtermembrane.9.2 Sample Filtration:9.2.1 Repeat the procedure described in 9.1.1.9.2.2 Thoroughly agitate the sample bottle (Note 8), andthen remove the cap.NOTE 8Other containers may be substituted providing they areidentified in the results. The sample bottle will of neces
35、sity remain thestandard container.9.2.3 Immediately remove the funnel cover, pour the samplecontents into the funnel, and recover. Place approximately 50mL of rinse liquid in the bottle, recap, and agitate. Pour therinse liquid into the funnel and cover.NOTE 9Where a filtration time is required as f
36、or military hydraulicfluids, apply suction of 47 to 57 kPa (356 to 436 mm Hg) before rinsing,and record the time required to filter the specimen. The bottle is thenrinsed twice into the funnel as described.9.2.4 Turn on the vacuum and allow the sample to filter untilone third remains. Lift the cover
37、 and carefully wash the funnelwalls with rinse liquid (Note 5). Replace the cover and filteruntil the membrane is dry. Remove the cover, holding device,and funnel, then release the vacuum immediately. Using theforceps, transfer the membrane filter to the petri dish. Label thepetri dish giving the sa
38、mple volume and identification. Thefilter is now ready for particulate contamination analysis.9.2.5 For permanent storage, required on military hydraulicfluids, sandwich the membrane between clean glass slideshinged together with transparent tape and seal the remainingsides with tape.10. Keywords10.
39、1 liquid sample handling; membrane filters; particulatecontaminationASTM 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
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42、d a fair hearing you 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).F311083
