1、Designation:F31108(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 originaladoption or
2、,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()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 contamina
3、tion 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
4、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 measurement are included i
5、n 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 Nonvolatile Matter in V
6、olatile 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Specification for Commercial HexanesD2021 Specification for Neutral Detergent,40 PercentAlky-lbenzene Sulfonate Type(Withdrawn 2000)3F302 Practice for Field Sampling of Aerospace Fluids inContainersF303 Practices for Samplin
7、g 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 a filter withpore size no
8、 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 processing forvisual contamination
9、 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 measuring the sample volume,the funnel
10、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-Holding DeviceA provision
11、 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 units acceptable to ASTM).5.7 Forceps,unse
12、rrated 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 Nov.1,2013.Published November 2013.Origina
13、llyapproved 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 information,refer to the standards Document Summary
14、 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 States1 5.9 Membrane Filter,pore size no greater than half the sizeof the smallest partic
15、le 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.NOTE1When testing military hydraulic fluids,a white cellulosemembrane of 0.45-m pore size,capabl
16、e 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 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.
