1、Designation: F311 08 (Reapproved 2013)Standard Practice forProcessing Aerospace Liquid Samples for ParticulateContamination Analysis Using Membrane Filters1This standard is issued under the fixed designation F311; the number immediately following the designation indicates the year of originaladoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the processing of liquids in prepa-ration for particul
3、ate 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 randomlydistributed
4、 on the filter surface 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 measuremen
5、t are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2D287 Test Method for API Gravity of Crude Petroleum andPetroleum Products (Hydrometer Method)D1078 Test Method for Distillation Range of Volatile Or-ganic LiquidsD1193 Specification for Reagent WaterD1353 Test Method for Nonvo
6、latile Matter in Volatile Sol-vents for Use in Paint, Varnish, Lacquer, and RelatedProductsD1836 Specification for Commercial HexanesD2021 Specification for Neutral Detergent, 40 PercentAlky-lbenzene Sulfonate Type (Withdrawn 2000)3F302 Practice for Field Sampling of Aerospace Fluids inContainersF30
7、3 Practices for Sampling for Particles in AerospaceFluids and ComponentsF312 Test Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membrane Filters3. Definition3.1 filtered liquid dispenseras used in this practice, adispenser capable of delivering rinse liquid through
8、a filter withpore 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 F302 and Prac-tices F303. It will provide the optimum sample process
9、ing forvisual contamination methods such as Method F312, and TestMethod F314.5. 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 measurin
10、g the sample volume, 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.
11、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 unidirectionalflow filtered air, in which uncovered components may beplaced.5.6 Vacuum SourceMinimum vacuum gage reading of 61kPa (or other metric uni
12、ts acceptable to ASTM).5.7 Forceps, unserrated tips.5.8 Filtered Liquid Dispenser.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 approved No
13、v. 1, 2013. Published November 2013. Originallyapproved in 1969. Last previous edition approved in 2008 as F311 08. DOI:10.1520/F0311-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume i
14、nformation, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.9 Membrane Filter, pore
15、size no greater than half the sizeof the smallest particle being considered for measurement. Thefilter shall 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 f
16、luids, 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, glass. Plastic Petri dishes may be usedonly if the selected plastic is known
17、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 Suspension, to be used in calibra-tion of the funnel.5.14 Slides, glass, 50 by 50-mm
18、.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 specifications of the Commit-tee on Analytical Reagents of the American Chemi
19、cal Society,where such specifications are available.4Other grades may beused, provided it is first ascertained 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 b
20、e understood to mean reagent water conformingto Specification D1193, Type III or clearer.6.3 Detergent, free-rinsing. Material conforming to Specifi-cation D2021 is suitable.6.4 Isopropyl Alcohol, acetone-free.56.5 Solvent, conforming to the following requirements(Note 2):6.5.1 Distillation Range, i
21、nitial boiling point 27C (80F)min; dry point 71C (160F) max, as determined in accordancewith Test Method D1078.6.5.2 API Gravity, 70 deg min, as determined in accordancewith Test Method D287.6.5.3 Residue, 0.004 g/100 mL max, as determined inaccordance with Method D1353.NOTE 2Commercial hexanes conf
22、orming to Specification D1836meet this requirement. Other chlorinated solvents, conforming to theMontreal 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 v
23、entilation 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. Preparation of Apparatus7.1 Wash the apparatus thoroughly in a solution of liquid
24、detergent 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 wherehardness or contamination increase the blank count over the allowablelevel.7.2
25、 Sample Bottle PreparationRepeat the procedure of 7.1for both the sample bottles and caps, then allow them to dripdry. 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 4I
26、t 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 described in9.1. Filter the suspension through the membrane filter andallow to dry.
27、 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 measurements and calculate the areaas follows:Area 5 D2/4 (1)8.3 Mark the funnel to
28、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 the container and rinsewith filtered liquid. Place the membrane on the support, lo
29、werthe 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 cover and pour the contents of thebottle into the funnel. Place approximately 50 mL
30、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 down the funnel walls with rinse liquid (Note 5). Replacethe cover and filter until th
31、e 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 choose to subtract the blank from his sample counts, ormay establish a maximum standard
32、for particles in the blank.4“Reagent Chemicals, 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 Y
33、ork, NY, and the “United StatesPharmacopeia.”5Material conforming to USP XVII, 1965, p. 995 is suitable.F311 08 (2013)2NOTE 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.NOT
34、E 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 9.1.1.9.2.2 Thoroughly agitate the sample bottle (Note 8), andthen remove the cap.NOTE 8Ot
35、her 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 the funnel, and recover. Place approximately 50mL of rinse liquid in the bottle, rec
36、ap, 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 the time required to filter the specimen. The bottle is thenrinsed twice into the funn
37、el 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 membrane is dry. Remove the cover, holding device,and funnel, then release the vacuum im
38、mediately. 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 permanent storage, required on military hydraulicfluids, sandwich the membrane between
39、 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 respecting the validity of any patent rights asserted in connection with any item men
40、tionedin 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.This standard is subject to revision at any time by the responsible technical committee
41、 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 International Headquarters. Your comments will receive careful consideration at a meetin
42、g 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 below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO
43、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/).F311 08 (2013)3
