1、Designation: F 311 97 (Reapproved 2002)Standard 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 adopt
2、ion 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.1. Scope1.1 This practice covers the processing of liquids in prepa-ration for parti
3、culate contamination 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 randomlydistribu
4、ted on the filter surface for subsequent contaminationanalysis methods.1.3 The practice describes procedures to allow handlingparticles in the size range between 2 and 50 m with minimumlosses during handling.2. Referenced Documents2.1 ASTM Standards:D 287 Test Method forAPI Gravity of Crude Petroleu
5、m andPetroleum Products (Hydrometer Method)2D 1078 Test Method for Distillation Range of VolatileOrganic Liquids3D 1193 Specification for Reagent Water4D 1353 Test Method for Nonvolatile Matter in VolatileSolvents for Use in Paint, Varnish, Lacquer, and RelatedProducts3D 1836 Specification for Comme
6、rcial Hexanes3D 2021 Specification for Neutral Detergent, 40 PercentAlkylbenzene Sulfonate Type5F 302 Practice for Field Sampling of Aerospace Fluids inContainers6F 303 Practices for Sampling Aerospace Fluids from Com-ponents6F 312 Methods for Microscopical Sizing and CountingParticles from Aerospac
7、e Fluids on Membrane Filters73. Terminology Definition3.1 filtered liquid dispenseras used in this practice, adispenser capable of delivering rinse liquid through a filter withpore size no larger than half the size of the smallest particlebeing considered for measurement.4. Significance and Use4.1 T
8、his 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 contamination methods such as Method F 312, andTest Method F 314.5. Apparatus and Materials5.1 Filtration FunnelThe funnel
9、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 volume, the funnel shallbe calibrated within 62 % of the required volume.5.2 Membrane Filter SupportEither a fritted-glass
10、,sintered-metal, or stainless steel screen may be used. Thesupport shall be so designed as to enable attachment to avacuum flask.5.3 Vacuum Flask.5.4 Funnel-Holding DeviceA provision should be madefor the dissipation of static electricity from the funnel.5.5 A clean bench or hood, supplied with unid
11、irectionalflow filtered air, in which uncovered components may 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 small
12、est particle being considered for measurement. Thefilter shall have an imprinted grid on 3.10 6 0.02-mm centers.1This practice is under the jurisdiction of ASTM Committee E21 on SpaceSimulation andApplication of Space Technologies and is the direct responsibility ofSubcommittee E21.05 on Contaminati
13、on.Current edition approved April 10, 1997. Published February 1998. Originallypublished as D 2391 69. Redesignated F 311 in 1970. Last previous editionF 311 78 (1992).2Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 06.04.4Annual Book of ASTM Standards, Vol 11.01.5Annua
14、l Book of ASTM Standards, Vol 15.04.6Annual Book of ASTM Standards, Vol 10.05.7Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.The color shall be chosen to provide maximum contrast withthe par
15、ticulate 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 square centimeter per minute at 93 kPa (or other metric unitsacceptable to ASTM) and 25C is required.5.10 Petri Dishes,
16、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 to indicate sample volume.5.12 Plastic Film, 0.002-in. (0.05-mm) minimum thickness.5.13 Contrasting Pigment Suspens
17、ion, 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 chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the
18、specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.8Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determinat
19、ion.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, free-rinsing. Material conforming to Specifi-cation D 2021 is suitable.6.4 Isopropyl Alcohol, acetone-free.96.5 Solven
20、t, 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 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 m
21、L max, as determined inaccordance with Method D 1353.NOTE 2Commercial hexanes conforming to Specification D 1836meet this requirement. Other chlorinated solvents, conforming to theMontreal conference on control of chlorinated fluorocarbons may besubstituted where solvent presents a safety hazard, pr
22、oviding 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 the userand shall be compatible with the sample liquid the plastic film(see section 5.12) and the membrane filter.7
23、. 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 remove the water; thenrinse twice with filtered solvent.NOTE 3Distilled or deionized water shall be used in areas
24、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 them todrip dry. Place a piece of plastic film that has been rinsed withfiltered liquid over the mouth of the bottl
25、e. 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 Calibration8.1 Disperse a small quantity of pigment into 100 mL ofliquid in a glass bottle. Prepare for a filtration as
26、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 thepigment stain at three diameters 0, 45 and 90, with a verniercaliper to the nearest 0.1 mm.8.2 Average the three m
27、easurements 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 toremove remaining pigment from the funnel surface.9. Procedure9.1 Blank Analysis Filtration:9.1.1 Remove a membrane from
28、 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 liquid equal to the amountof fluid used in the routine sample filtration in a sample bottleand agitate. Remove the c
29、over 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 the vacuum and allow the liquid to filter untilapproximately one third remains. Lift the cover and carefullywash dow
30、n 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 turnoff the vacuum immediately. Remove the membrane using theforceps and place it in a petri dish labeled “Blank.” The usermay choos
31、e to subtract the blank from his sample counts, ormay establish a maximum standard for particles in the 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.8“Reagent Ch
32、emicals, 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 StatesPharmaco
33、peia.”9Material conforming to USP XVII, 1965, p. 995 is suitable.F 311 97 (2002)2NOTE 7When filtration is completed the rate of repressurization shallbe such that no fluid agitation shall occur which could re-wet the filtermembrane.9.2 Sample Filtration:9.2.1 Repeat the procedure described in 9.1.1.
34、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 necessity remain thestandard container.9.2.3 Immediately remove the funnel cover, pour the samplecontents into
35、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 for military hydraulicfluids, apply suction of 47 to 57 kPa (356 to 436 mm Hg) before rinsing,and record th
36、e 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 and carefully wash the funnelwalls with rinse liquid (Note 5). Replace the cover and filteruntil the memb
37、rane 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 sample volume and identification. Thefilter is now ready for particulate contamination analysis.9.2.5 For pe
38、rmanent storage, required on military hydraulicfluids, sandwich the membrane between clean glass slideshinged together with transparent tape and seal the remainingsides with tape.10. Keywords10.1 liquid sample handling; membrane filters; particulatecontaminationASTM International takes no position r
39、especting 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, and the riskof infringement of such rights, are entirely their own responsibility.Thi
40、s 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 standardsand should be addressed to ASTM Inte
41、rnational 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 Committee on Standards, at the address shown
42、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).F 311 97 (2002)3
