1、Designation: F51/F51M 00 (Reapproved 2007)1Standard Test Method forSizing and Counting Particulate Contaminant In and OnClean Room Garments1This standard is issued under the fixed designation F51/F51M; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case 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.1NOTEEditorial changes were made throughout in March 2013.1. Scope1.1 This test method covers the d
3、etermination of detachableparticulate contaminant 5 m or larger, in and on the fabric ofclean room garments.1.2 This test method does not apply to nonporous fabricssuch as Tyvek (trademarked) or Gortex (trademarked). It onlyapplies to fabrics that are porous such as cotton or polyester.1.3 This test
4、 method provides not only the traditional opticalmicroscopic analysis but also a size distribution and surfaceobscuration analysis for particles on a fine-textured membranefilter or in a tape lift sample. It utilizes transmitted illuminationto render all particles darker than the background for gray
5、 leveldetection. Particles collected on opaque plates must be trans-ferred to a suitable membrane filter.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be
6、 used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard may involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It i
7、s the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1216 Practice for Sampling for Particulate Contaminationby Tape LiftF25 Test Metho
8、d for Sizing and Counting Airborne Particu-late Contamination in Cleanrooms and Other Dust-Controlled Areas2.2 Institute of Environmental Sciences and Technology(IEST) Document:3IEST-RP-CC003.2, Garment System Considerations forCleanrooms and Other Controlled Environments3. Terminology3.1 Definition
9、s:3.1.1 fiber, nparticle longer than 100 m and with alength-to-width ratio exceeding 10:1.3.1.2 micrometre (m), nSI unit of length which is 10-6ofa metre or approximately 0.00004 in.3.1.3 particle size (L) (m)major projected dimension of aparticle.4. Summary of Test Method4.1 Filtered air is drawn t
10、hrough five designated 0.01-m21.5-in.2or approximately 0.01-ft2 areas of a single thicknessof the garment fabric at a rate of 14 L/min 0.5 cfm for aperiod of 1 min for each area.4.2 The air drawn through the garment subsequently passesthrough a membrane filter disk, impinging the entrainedparticles
11、upon the filter surface.4.3 The filter disk is then examined microscopically forparticles removed from the garment.4.4 For particles larger than 5 m, use optical analysis. Forparticles smaller than 5 m, use automated image analysis.4.5 Cleaning and counting techniques are in accordancewith those est
12、ablished in Section 10.1This test method is under the jurisdiction of ASTM Committee E21 on SpaceSimulation andApplications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition approved April 1, 2007. Published April 2007. Originallyapproved in
13、1965. Last previous edition approved in 2002 as F51 - 00(2002)1. DOI:10.1520/F0051_F0051M-00R07E01.2For 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 Doc
14、ument Summary page onthe ASTM website.3Available from Institute of Environmental Sciences and Technology (IEST),Arlington Place One, 2340 S. Arlington Heights Rd., Suite 100, Arlington Heights,IL 60005-4516, http:/www.iest.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959. United States15. Significance and Use5.1 The test method for particulate sizing and numbers ongarments is nondestructive and may be used to evaluate thecontamination levels of fibers and particles on and in cleanroom garments. The test may be used for evaluating thecleanli
16、ness levels of new or newly cleaned garments. It alsomay be used to evaluate the extent of fiber and particulatecontamination on garments that have been worn, if necessary.For this application, it is necessary to sample representativeareas of the garment fabric.6. Apparatus6.1 Filter Assembly and Ad
17、apter, see Fig. 1 and Fig. 2.6.1.1 Filter Holder, aerosol open type having an effectivefilter area of 960 6 25 mm2.6.2 Vacuum Pump or Aspirator, capable of operating at apressure of 7 kPa 500 torr with a flow rate of 14 L/min 0.5cfm.6.3 Flowmeter or Orifice, calibrated and having a capacityin excess
18、 of 14 L/min 0.5 cfm, or a limiting orifice calibratedwith the pump, filter holder, and filter used for this test methodat a flow rate of 14 6 0.5 L/min 0.50 6 0.02 cfm. Ensure,visually, that the orifice is free of obstructing matter beforeeach test.6.4 Membrane Filters:6.4.1 Black, 0.80-m pore size
19、, 47-mm diameter with3.08-mm imprinted grid for fabric particles.6.4.2 White, 0.80-m pore size, 47-mm diameter withoutimprinted grid for fabric particles and automated image ana-lyzer.6.4.3 White, 5.0-m pore size, 47-mm diameter (air prefilterused with the filters in 6.4.1 and 6.4.2).6.4.4 Plastic P
20、etri Slides with Covers ,4plastic petri dishes,60-mm diameter or glass microscope slides, 50 by 75 mm.6.5 Binocular Microscope with ocular-objective combina-tions to obtain 40 to 45 and 90 to 150 magnifications. Latterobjective shall have a numerical aperture of 0.15 min.6.6 Programmable Image Analy
21、zer, a Computer-Driven Mi-croscope Which Counts and Sizes Particles With AutomatedStage and Automated Focus Interface:6.6.1 Microscope, with a large glass platform automaticstage and automated focus.6.6.2 Objectives and Projection Lenses, to generate a pixeldimension of about 5 m or less.6.7 Forceps
22、, with unserrated tips.6.8 Normal Counter, (2 gang) or equivalent. See Note 1.NOTE 1The Veeder Root counter has been found satisfactory for thispurpose.6.9 Microscope Lamp, 6 V, 5 A high intensity.6.10 Stage Micrometer, standard 0.01- to 0.1-mm scale.6.11 Ocular Micrometer Scale, 5-mm linear scale w
23、ith 100divisions.6.12 Standard Counting Specimens.7. Sampling Requirements7.1 The sample shall be collected by drawing air filtered to5 m through the test garment, impinging the garment-borneparticles on the membrane filter. The filter surface mounted inthe open-type aerosol filter holder shall be p
24、laced on the outersurface of the test garment. The garment is firmly clamped tothe filter holder by means of the air-filter adapter. Duringsampling, the garment shall be hung or carefully positioned tominimize extraneous contamination.7.2 The standard sample of this test method is secured withthe pa
25、ssage of 14 L0.5 ft3 of air through the test fabric duringa 1-min period at each of five sampling areas as shown in Fig.3. One sampling area is adequate for caps, helmets, towels,wipers, and booties with plastic soles. Two areas are suggestedfor all-fabric booties.4The sole source of supply of the a
26、pparatus (Analyslides) known to thecommittee at this time is Gelman Sciences, Ann Arbor, MI. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committe
27、e,1which you may attend.FIG. 1 Filter AssemblyFIG. 2 AdapterF51/F51M 00 (2007)127.3 Locations are approximate and may be modified to suita specific design factor by agreement.8. Preparation of Apparatus8.1 Before sampling when using only a microscope, removedirt and dust from the filter holder by wa
28、shing in a free-rinsingdetergent, ketone-free, isopropyl alcohol and submicrometer-filtered reagent grade petroleum ether (boiling range from 30 to60C).8.2 Maintain the laboratory equipment and area used forcounting and sizing the particles in a condition of cleanlinessparallel or superior to the ar
29、ea sampled. Good clean room andcontamination control practices should be followed. Plasticmicroscope hoods have proven satisfactory as covering, in aclean room, in the absence of a laboratory clean hood.8.3 Personnel performing sizing and counting operationsshall wear garments and behave in a manner
30、 appropriate to thecleanliness conditions in which they are working.8.4 Clean and prepare the microscope slides and petri dishesfor preserving the membrane filter and specimen. Lens tissueproperly used is satisfactory for this operation.8.5 Handle hazardous chemicals used in the test methodwith reco
31、gnized precautions.8.6 Establish a background count on membrane filters byexamining each filter used for referee purposes. Examination at40 to 50 magnifications through the microscope will reveallow or high background count.8.7 Make a background count (Note 2) following themicroscopic methods outlin
32、ed in this test method, upon anyfilter with a contamination level approximating 10 % or greaterof the estimated test sample (Note 3). This count will besubtracted from the total count (Pt) obtained in 10.1 for eachsize range.8.8 Place acceptable filters in clean petri dishes and cover.Identify the d
33、ishes for test use.8.9 When using an automated image analyzer, preparation issimilar to the preceding except that the white, ungridded0.08-m filter is used.NOTE 2For routine work, a background count on two filters per boxof 100 is adequate under present rigid production methods.NOTE 3If the backgrou
34、nd count is estimated to be greater than 10 %of the total count from a 0.3-m310-ft3 specimen, a larger sample 0.4- or0.6-m315- to 20-ft3 volume may be used to eliminate background countprocedure.9. Sampling9.1 With the aid of laboratory pressure tubing, connect thefilter holder to a source of vacuum
35、 which has been foundadequate to produce a flow rate of 14 L/min 0.5 cfm, atvacuum conditions test (pressure of 5 kPa or 350 torr). Theholder may be open, may contain a limiting orifice (Fig. 4), orFIG. 3 Clean Room Garment Sampling LocationsF51/F51M 00 (2007)13may be connected to the flowmeter. If
36、a flowmeter is usedbetween the filter holder and vacuum source, correction to thestandard temperature and pressure must be made to determineactual standard temperature and pressure flow.9.2 With clean forceps, carefully remove the appropriatemembrane filter from the container and place, with grid si
37、deup, when appropriate, on the screen support of the filter holder(Fig. 5). Twist the locking ring in place after placing thetapered adapter in position. Similarly, place the 5.0-m air filterin the top portion of the adapter by removing the O-ring fromthe adapter top, placing a 47-mm white filter on
38、 the supportscreen and replacing the O-ring. (This filter may be used formany tests.)9.3 See IEST-RP-CC003.3 for additional recommendationson the sampling of garments.9.4 When ready to sample, place the outer surface of the testgarment over the tapered (male) adapter. Firmly lock into testposition b
39、y placing the air-filter tapered (female) adapter overthe test portion of fabric.9.5 Apply vacuum at the predetermined flow rate of 14L/min 0.5 cfm for a period of 1 min for each area. Samplerequired areas (Fig. 3) by repeating 9.2.9.6 Remove the filter from the holder with forceps and placeit betwe
40、en the clean microscope slides, in a clean transportcontainer (see 6.4.4) or in a clean petri dish for transport to themicroscope counting area. The membrane must be cleanedbefore placing it in the transport container.10. Microscope Analysis Procedure10.1 Place the ocular micrometer in one eyepiece.
41、 Using astage micrometer, calibrate the measuring eyepiece (ocularmicrometer) for each magnification (Fig. 6). A whipple disksimilarly calibrated is satisfactory for many inplant investiga-tions.10.2 Knowing the subdivisions of the stage micrometer(top), the divisions of the measuring eyepiece (bott
42、om) may besized from it (Fig. 7).NOTE 4Example: Stage the micrometer 100 m per major division, 10m per minor division: 100 divisions of the measuring eyepiece subtend1050 m, one division of the measuring eyepiece = 10.5 m.10.3 Remove the petri dish cover, then remove the filterfrom the petri dish an
43、d place it, with filtering surface up, on a50- by 76-mm 2- by 3-in. microscope slide. Greasing theslide lightly with silicone stopcock lubricant before mountingthe filter will assist in holding the filter flat in place.10.4 Adjust the external light source to obtain maximumparticle definition with a
44、n illumination angle of approximately45. High-intensity illumination is a critical requirement.10.5 Use a magnification of approximately 45 for countingparticles 50 m or larger and approximately 100 for particlessmaller than 50 m. Greater magnifications may be advanta-geous for examination to identi
45、fy particles.NOTE 5Analysis for particles in the 0.5- to 5.0-m size range may beachieved by using transmitted light techniques, after rendering the whitefilter transparent by placing the filter on immersion oil of refractive index1.515. A magnification of at least 500 is required. For transmitted li
46、ghtmicroscopy, a white filter must be used (instead of black filter) since onlythe white filter can be rendered transparent with immersion oil. If asmaller pore size filter is used, the flowmeter used and the limiting orificewill require calibration with the filter holder and filter in place.FIG. 4
47、Inserting a Typical OrificeFIG. 5 Placing the Filter on a Typical Screen SupportFIG. 6 Typical Counting and Sizing Microscope and Illuminator(see Test Method F25)F51/F51M 00 (2007)1410.6 Particles should be counted and tabulated in two sizeranges: particles greater than 50 m and particles 5 to 50 m.
48、Particles smaller than 5 m are not to be counted by the manualcounting method. The size of particles is determined by itsgreater projected dimension. Fibers are counted as particlesand are counted separately as fibers.10.7 Test Method of Counting Particles:10.7.1 Adjust the microscope focus and lamp
49、 position sothat the maximum clarity of filter surface and particle definitionis obtained.10.7.2 With the lower magnification (approximately 45),count the particles in a number of grid squares selected atrandom until meeting the statistical requirements in 10.9.10.7.2.1 For particles larger than 50 m, use the manualcounter (6.8).10.7.3 At the higher magnification (100), count the num-ber of particles in the 5- to 50-m range in a number of gridsquares selected at random until meeting the statistical require-
