I METRIC I XIL-Sm-1246C 11 April 1994 SUPERSEDING MIL-STD-l246B 4 September 1987 MILITARY STMDARD PRODUCT CLEANLINESS LEVELS CONTAMINATION CONTROL PROGRAM .-. .. AMSC N/A distribution is unlimited FSC 3694 Approved for public release;
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I METRIC I
XIL-Sm-1246C11 April 1994
SUPERSEDINGMIL-STD-l246B4 September 1987
MILITARY STMDARD
PRODUCT CLEANLINESS LEVELS
CONTAMINATION CONTROL PROGRAM
.-...
AMSC N/A
distribution is unlimited
FSC 3694Approved for public release;
.—
I
I
MIL-sTD-1246C
FOREWRD
!1. This military standard is approved for use by all
Departments and Agencies of the Department of Defence.
I
2. Beneficial comments ( recommendations, additions,deletions) and any pertinent data which may be of use inimproving this document should be addressed to: Commander, U.S.Army Missile Conmand, Al’TN: AMSKI-RD-SE-TD-ST, Redstone Arsenal,
AL 35898-5270 by using the Standardization Document ImprovementProposal (DD Form 1426) appearing at the end of this document orby letter.
3. This standard contains requirements for theestablishment of a uniform method for specifying productcleanliness levels and contamination control programrequirements.
.’.
MIL-sTD-1246C
CONTENTS
I
I
1. SCOPE ............................s”+=”.==--”. -“””-”11.1 scope ......................*..*.. ...0... ......1
1.2 Use .......................-.---.-.-.---”” -.-..11.3 Applicability .................-*=oo.0=0..o=”o.11.4 Background ...............-...00--==o=oo=o”ooc “11.5 Safety ...................-+.””.O=”=O=”D.OOO.O”l
2. APPLICABLE DKUMHTS .........*..... ...==”””””””””””22.1 Governxnent documents.. ........................22.1.1 Stiecifications, stanardst and hsn~ks””o --”.22.2 Non-Gove rnment publications.. ........-.O...OOOQ2.3 Orderof precedence. ..........................4
3.3.13.2
3.33.43.53.63.73.83.93.103.113.123.133.143.15
DEFINITXWS ...............--..=oo=o”o ***o”*** ‘**-*”5Cleanliness level .............................5Collected volatile condensable material(CVCM) ..............● 0...................----.5
Contaminant ..............-.--””=.-.””.””..- ..-5Contamination ...-..-..-..-..-DO”-”.”.”.-”= -“”.5Contamination Control. ...............=N...... .5Demonstrated equivaleXAcee.............”.....OO.5
Micrometer @n) ........................*..* ● .-5
Non-vo18tile residue (Hloa.eooo.a=o=”=”””.” “sParticle percent area coverage ................-5Particle size..o..... .....-..”do”=””=”=-.== “==5Point of contact .........-..OO.O””-O-==”==” ““”5Significant surface.. ...-.-...”..OOOO O”===“=.-6Total mass loss (m) ........oOoaOeOOO*●=o=c”. fiTurbidity ..........................0.........*6
Volatile condensable material (vCM)............6
4. G~ RWJI REGENTS ........*.-.....* ●“””””””””””””74.1 Contamination control program ..................74.1.1 Responsibility .............*.o=o===”Dco-=0===0 74.1.1.1 Prescribing products cleanliness ...............74.1.1.2 Achieving and maintaining product cleanliness.74.1.1.3 Assuring the integrity and continuity of the
contamination control effort ...................74.2 Methods for specifying products cleanliness
levels ................-....s”-”..”-”-.””.”..””74.3 Log-log2 distribution of particles ............lO
5. DETAILED REQUIREGENTS..*..........+*. ●...****”””””13
5.1 Cleanliness levels... .............O...O.””” ““135.1.1 Application of cleanliness levels .............l3
MIL-STD-1246C
5.1.25.1.2.15.1.2.25.1.2.35.1.2.45.1.2.55.1.2.65.1.2.75.25.2.15.2.25.2.35.2.45.35.4
5.4.15.4.25.4.35.4.45.4.55.4.65.4.75.4.85.4.9
6.6.16.26.36.46.5
I.II .III.
IV.v.
Measurement of cleanliness levels .............ldDirect measurement ...........................14Extractive Sampling ..........................14Indirect sampling ...................=-...””” -14Percent area coverage ..........--.....-”. ..--15Alternative particle count specifications. ....15Volatile condensable mtarial .................16~rbidity ............=..-.=OO-”-OD ==O=O.O” .0017Statistical analysia of data. .o........o......17Poisson statistics.. .......O.O.OF.-.”.”.” “...17Student’8t @WIYs%B =”””-D.Y~..”...0.0-C.-...-=7Transformation of data .......................17Number ofsaxrq)les............................18Recording of data.... ..........=..000=o.o”...18Detailed requirements for contaminationcontrol plan .................................18Design requirements ..........................19
Contamination Control Responsibility ..........19Processes and controls ...............F>.......19Environmental Control. .......................19Sub-tier contractors.. ........O..............19Calibrations procedures ......................19Quality control do.-..... ..-.......-..-.......19Product protection ...........................20Personnel ...............---..-””...--”..-.. .=20
NOTES................*”. ● .**”*””””.”.” ”””””...... -21Intended use ......=-.. ....owoo”.=~~”......... 21Issue of DODISS .............=-.-.”..”..”..”.. 21Additional info-tion .......................21Subject te~ {key W=d) listing”...”22.......”22Changes frm previous issue ..................22
Particle Cleanliness Levels ........................9Non-Volatile Residue Cleanliness Levels ............llSanpling and measurement technics for surfaces,
liquids, and gases ..............................15Calculating particle percent area coverage .........l6Gross cleaning processes ..........................26
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MIL-sTD-1246C
FIGURE1. Product Cleanliness levels ...................22
APPENDIX CLEANING METHODS AND WTERIALS” ...............23
10. GENERAL ...............-0.-..o*=.-.*..-o*..... ●*”.=2310.1 scope .....-..-....-””.” ““”.””””””””””””””.”=”2320. APPLICABLE DOC~S ..............................23300 DEFINITIONS.../ ..........o...00o0=*.=**.=*... ●..--2340. GENERAL REQUIR.EMENTs............-..= ““..”....”...”2340.140.1.140.1.1.140.1.1.1.140.1.1.1.240.1.1.1.340.1.1.1.440.1.1.1.540.1.1.1.640.1.1.1.740.1.1.1.840.1.240.1.2.140.1.2.240.1.2.2.140.1.2.2.240.1.2.2.340.1.2.2.440.1.2.2.540.1.2.2.640.1.2.2.740.1.2.2.840.1.2.2.940.1.2.350.50.150.250.360.60.160.1.160.1.260.1.360.2
Cleaning methods and materials ................23Gross cleaning ...............................23Gross clea.ningtYPes. ........................24Acid cleaners ............-.””o-=””0000=00= ““=24Alkaline cleaners ............................24Detergents and mild cleaners .................24Organic solvent cleaners .....................24Tap water and deionized water ................24Neutralizing and passivating solutions ........24Mechanical cleaning. .........................24Gross cleaning processes .............;:.......25Precision cleaning ...........................25precision cleaning solutions/fluids ...........25Precision cleaning methods/processes ..........25Solution cleaning ............................27spray cleaning .............-ODO.=-””””””””” ““27Sonic cleaning ...............................27Vapor cleaning ........................O.==- .-~~Flush cleaning ● .......*.**.- ● ...**. ● .*..*- ● -*spinrinse/drying.*.=. .~=-.=-=..”=”=””””=”..= 28Electropolishing and ch~cal Xlishing. -=.===28Other methods ................................28Ozone depleting substances ...................28Handling during cleaning. ....................28
PROTECTION ................=~..*.o*”=o*.=oo.* ●*-*.*29Cleanliness protection .......................29Precision clean packaging ....................29Storage ....e......a........-...”.”.”.””.”..””29
INSPECTION .................=.....”.=”-.”=”..-. ‘=0”30Inspection ......................”” ..O.OGOOO“+30Breaking of a closure ........................30Inspection requiring opening of a packaga ....3OTraceability .................*o*..o”o.o.”=.. “30Issue of DODISS ...............................30
..
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MIL-STD-1246C
I
1. SCOPE
1.1 f&QQg. This standard provides a basis and a uniformmethod for specifying product cleanliness levels and contaminationcontrol program requirements. The emphasis is on contaminants thatcause damage through pbsical interactions rather than chemicalinteractions.
1.2 Q. These requirements are unusual and are not requiredfor all products but are intended for use in milita~ procurementand design contracts for only those items where contaminationcontrol, by measurement for parts, components, or fluids, isnecessary to ensure reliability.
1.3 ~. When this standard is made part of aprocurement contract, the procuring activity shall be responsiblefor identifying the applicable requirements contained herein thatapply to the particular contract.
~.4 ~ The log-lo~ distribution of particles witha slope of 0.926 is based on a lognorxtaldistribution with themaximum number of particles at the lpm size. This lognormaldistribution was derived from measurements of precision. cleanedhardware and, therefore, is representative of cleaned products.Products exposed to contaminating environments can be expectad tocollect different distributions of particles.
1.5 ~. The use of the techniques and ~terialsdescribed here may haveenvironmental impacts.be consulted before the
significantAppropriateuse of such
health, safety, andsources of information shouldtechniques and materials.
MIL-STD-1246C
2. APPLICABLE DOCUMENTS
2.1.1 ~ Thefollowing specifications, standards, and handbooks fkrm a part ofthis document to the extent specified herein. Unless othexwisespecified, the issues of these documents are those listed in theissue of the Department of Defense Index of Specifications andStandards (DODISS) and the supplement thereto, cited in thesolicitation (see 6.2) .
STANDARDS
Federal
FED-STD-209 - Airborne Particulate CleanlinessClasses in Cleanrooms and CleanZones.
(Unless othemise indicated, copies of federal and militaxyspecifications, standards, and handbooks are ●vailable from theStandardization Documents Order Desk, Bldg. 4D, 700 Rotd+ns Ave.,Philadelphia, PA 19111-5094.)
2.2 ~. .
The following documentsform a part of this standard to the &tent specified herein.Unless Ot*misc specified, the i=ue Of tb dommmnts which areDOD adopt- am Choso listed in the issue of the =1SS cited inthe solicitation. Unless otherwise specified, the issues ofdocuments not listed in the ~DISS are the issues of the documentscited in the solicitation (see 6.2) .
AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)
ASTM E595 - Standard Test Method for Total MassLOss and Collected VolatileCondensable Materials from Outgassingin a Vacuum Environment
ASTM E1216 - Standard Practice for Sampling forSurface Particulate Contamination byTape Lift
AS’IU E1234 - Standard Practice for Handling,Transporting, and InstallingNonvolatile Residue (IWR) SqlePlates Used in EnvironmentallyControlled Areas for Spacecraft
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MIL-sTD-1246C
ASTM E1235 -
ASTM F25
ASTM F50
ASTM F52
JUXI14F302
ASTU F303
ASTM F306
ASI’114F307
Asmf F311
ASZ?4 F312
ASTM F318
ASTM F327
AS’IM F331
SCandard Test Method for GravimetricDeterdnation of Nonvolatile Residue(DIVR)in Environmentally Controlledkeaa for SpacecraftStandard Test Method for Sizing andCounting Airborne ParticulateContamination in Clean R- and OtherDust-Con&rolled Areas, Desi
Ffox
Electronic and Similar APp icationsStandard Practice for ContinuousSizing and Counting of AirborneParticles in Dust-Controlled Areas andCleanrooms Using Instruments Capableof De&acting Single Sub-Micrometer andLarger ParticlesStandard Test Method for Sizing andCounting Particulate Contaminants Inand On Clean Room GarmentsStandard Practice for Field Samplingof Aerospace Fluids in ContainersStandard Practice for SamplingAerospace Fluids fr~ ComponentsStandard Practice for SamplingPaxticulat@s froQ Man-Acce~sibleStorage Veo8els for Aero ape”Fluids
%by Vacuum Entxahunent Tec que(Genem!d Method)Standard Practice for SamplingPr*t3sur,lzedGa8 for Gas Analysis.Preati* for Pxx3using *respaceLiuuid SmmPlea for Particulatecomt~~~.i,~ *alyqis Using M*raneFiltersMethods for Microscopical Sizing andCounting Particles from AerospaceFluids on Membrane FiltersStanda* Practice for San@ingAirborne Particulate Contamination inClean Rooms for Handling AerospaceFluidsStandard Practice for Sqpling GasBlow Down Systems and Components forParticulate Contamination by AutomaticParticle Monitor MethodStandard Test Method for NonvolatileResidue of Halogenated Solvent Extractfrom Aerospace Components (Usin9Rotary Flash Evaporator)
MIL-STD-1246C
ASTM F1094 - Standard Test Methods forMicrobiological Monitoring of WaterUsed for Processing Electron andMicroelectronic Devices by DirectPressure Tap Sampling Valve and W thePre-Sterilized Plastic Bag Method
(Applications for copies of referenced AS~s should beaddressed to the American Society for Testing and Materials, 1916Race Street, Philadelphia, PA 19103-1187.)
SOCIETY OF AU’N3MOTIVE ENGINEERS, INC.
ARP 590 The determination of ParticulateCmt~nation in Liquids by theParticle Count Method.
ARP 743 Procedure for Determination ofParticulate Contamination of Air inDust controlled Spaces by the ParticleCount Method.
(Applications for copies W referenced SAE documents should bemade to th~ Society of Autonmtive Engineers, Inc., 400 CommonwealthDrive, Warrendale, PA 1$096.)
(Non-gwe rnment standards and other publications are normallyavailable from the organizations that prepare or distribute thedocuments. These doc~nts also may be available in or throughlibraries or other informational senices. )
2.3 ~. Xn the event of a conflict betweenthe text of this document md the references cited herein, the textof this doeument takes precedence. Nothing in this document,however supersedaa applicable laws and regulations unless specificexemption has been obtained.
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MIL-sTD-1246C
3. DEFINITIONS
1
3.1 . An established maximum allowableamount of contamination in a given area or volume, or on acomponent.
3.2 ● ‘Memass that outgasses from a material arid subsequently eondertses on acollector surface as specified in ASTM E595 expressed as apercentage of the initial specimen mass. See also Total Mass Loss.
3.3 . A specific type of contamination.
3*4”~. ●
. Ihawaatad nlatexu.
3.5 . Any organizti action taken tocontrol the level of contamination.
3.6 . The condition where a methodof measurement has pasBed a series of tests to show that it givesequivalent results to those of a standard measurement.
3.7 ~ . A unit of measurement equal. to one-millionth of a meter, or approximately thirty-nine millionths of aninch (0.000039 inch), or, 25 microns is approximately 0.001 inch.The micrometer has replaced the micron in the S1 system ofmeasurement.
3.8 ~e [~ Material remaining afterevaporation of a liquid. Units are determined by the test methodused .
3.9 Rm&imhke D~~~ ~~””- . The fraction of thesurface that is covered w particles, reported as total particleprojected area divided by total surface area.
3.10 ~ Rk. The maximum linear dimension of theparticle.
3.11 . A designated individual position inan organization, the occupant of which has the responsibility forassuring that contractual contamination control requirements aremet. This position is identified and serves as a focal point forall activities concerning contamination control.
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MIL-sTD-1246C
I3.12 ~ . my surface of an item or product
which is required to meet established cleanliness levelrequirements.
3.13 ~. The mass that outgases from amaterial, es specified in M,’R4E595, expressed as a percentage ofthe initial mass of the specimen.
I
3.14 ~. The cloudiness of a liquid caused by thepresence of finely divided suspended material.
3.15 1 i= . Gaseous productsreleased from a mateq,ial under s ecified conditions of teuqerature.-..,...and preseure, !that condense at “o’Ker”spec~f~-’e~Uitims oftemperature or pressure or both.
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MXL-STD-1246C
4. GENERAL REQUIR~S
4.1 .
4.1.1 .
4.1.1.1 . The responsibilityfor selecting or determining the degree of product cleanlinessshall rest with the engineering organization initially responsiblefor the product to be produced or processed.
4.1.1.2 ~~. . . . The
responsibility for achieving and maintaining product cleanlinessshall rest with the organization whose function is to process orproduce the product from the design and related spec~ficationrequirements.
4.1.1.3. The responsibility for a continuing
contamination control effort shall rest with a designated point ofcontact, as defined herein with the authority to assure that theproduct meets design and specification requirements.
4.2 .‘-.Only the
cleanliness level or levels specified for a particular product areapplicable to that product. Product cleanliness shall be specifiedin the following manner:
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MIL-sTD-1246C
MIL-STD-1246 LEVEL
I
‘t- z = Alternative or additionalcleanliness levels, consisting of oneor wmre abbreviations from thefollowing list and the mximumlimit(s) expressed in the unitsdescribed herein:px . ~rcent Area C9ver*PC = particle Count specified
independently of table I (see5.1.2.5)CVCM = Collected VolatileCemdenaablc Material inaccordance with ASTM E595VCM = Volatile CondensableMaterial determined by methodsother than ASTM E595NTU = Nephelometric Turbidityunits (eee S.aa.?).~ = Total Mass ti88, inaccordance with ASTM E595
Y = Non-volatile residue cleanliness leveldesignation from table II. ~-
= Numerical particle cleanliness level fromtable I.
Only the cleanliness level applicable to a particular productshall be specified. If no level is specified, then thedesignation shall be omitted. Exanples follow:
a. “MIL-STD-1246 Level 200”, refers to particulate only.
b. “MIL-S’ITlk1246Level 200F”, refers to particulate and NVR.
c. WIL-S~-1246 Level F“, refers to NVR only.
d. “MIL-STD-1246 Level 200F, CVCM=O.1%, ~=1%”, refers toparticulate, NVR, collected volatile condensable material, andtotal mass loss.
e. ‘MIL-STD-1246 Level 200, CVCM=O.1%”, referS toparticulate and collected volatile condensable material.
f. “MIL-STD-1246 Level CVCM=O.1%”, refers to collectedvolatile condensable material only.
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MIL-STD-1246C
TABLE I.
I
Level Particle Count per Count per Count perSize, pm 1 ftz 0.1 It? liter
1 1 1.0 1.08 10
5 3.02 285 ; ;:: 2.48 235 5 1.0 1.08 10
10 9.07ao : ,::: ,, 7.56 , ~, %
10 3.0 3.24 3010 1: 1.0 1.08 10
25 2 57 53025 z: 24.8 230
1; 3.4 3.67 34:: 25 1.0 1.08 10
50 5 166 179 1660.-.50 25 27.0 25050 :: 7.3 7.88 7350 50 1.0 1.08 10
100 5 1785 1930 17850100 15 265 286 26S0100 25 70 84.2 780100 11.9 110100 1:: 1?: 1.08 10
200 15 4189 4520 41890200 25 1240 1340 12400200 170 184 1700200 1:: 16 17.3 160200 200 1.08 10 .1.0
300 25 7455 8050 74550300 50 1021 1100 10210300 100 95 103 950300 250 2.3 2.48 23300 300 1.0 1.08 10
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J61L-$TD-1246C
Level
500500500500
7507507s0750750
10001000100010001000
Particle
Size, lJm
50100250500
50100250500750
100250500750
1000
Count per
I
Count per1 ftz 0.1 U?
118171100
261.0
9580789193148.11.0
426S81022
394.81.0
12800119028.11.08
1050009630231
8.751.08
46100110042.15.181.08
Count perliter
11817011000
26010
958070891902140
8110
42658010220
3904810
11 Limite on-particle count at indicated particle size for surfaceor liouid-to meet the level of cleanliness. Sampliw areas otherthan ~.1~ shall be calculated to the basis of O.l&. Aras XMybe @stimated if total area is considered by both parties to be teodifficult to measure within two significant figures. Thiscotidition shall be noted and low/high ranges shall
3used ● Parts
with a total significant surface area less than 0.1 and whichhave had the entire critical surface area saupled shall be acceptedon the basis of actual count.
4.3 m-lqz~ of ~ The log-log2distribution of acceptable particle contamination is shown infigure 1.
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MIL-sTD-1246C
TABLE II. ~on-v~e .re~ 1ew 1s
Level Limit, NVR Limit, NVRmg/o.lxf? * 1/ mg/liter
(or ug/cr?)
A/100 0.01Af50 0.02 ;:;A/20 0.05 0.5A/10 1.0A/5 ;:: 2.0A/2 0.5 5;0A 1.0 10.0B 2.0 20.0c 30.0D ::: 40.0E 5.0 50.0F 70.0G J:: 100.0H 15.0 150.0J 55.0 250.0 -
1/ Limits on non-volatile residue (IWR, w) for surface,liwid,or gag to meet the level of cleanliness.
3One square foot = 0.0929 m .
11
s
MIL-STD-I-246C
2
1
0Parucb*,(@tx)*
FIGURE 1. t
12
MIL-STD-1246C
5. DETAILED REQUIREMENTS
5.1 Tables I and II prescribe thecleanliness levels established to provide a uniform set of criteriafor specifying product cleanliness in terms of particles or non-volatile residues (NVR) or both. Use of these cleanliness levelsprovides a basis for specifying and determining conformance tocleanliness requirements.
Unless otherwise specified, cleanliness levels shall be interms of maximum
runts per unit extent (area, volume, mass) , such
as counts per 0.1 . Use of a particular unit of extent does notimply thbt the measurements’ are to be ‘taken over this extent, butrather that the total amount is to be divided by the total atent.In general, higher accuracy is fostered by the measurement oflarger extents.
For contaminant levels other than particles or. NV% limits
shall be desigxmtmd by tie u9eriw unit8 preecribe&i- .5.1.1.,, .,
5.1.1 of The cleanlinesslevels of tabl~ 1 and 11 8hall apply to surfaces, ass-blios,components, fltiitls,or mterials. Documentation shall includesampling detaila and acceptance criteria. The following units ofmeasure shall be used:
la) ~. Partialu categorized by size and ccbunt pez0.1 square meter (1 square foot = 0.0929 square meter) x?fsignificant surface ar.a (areas may be estimated). Perc&nt areacoverage (PM!) measured as total particle pro$eoted area divided bytotal significant surface ●rea. WR in milligrams per 0.1 swaremeter of significant su”rfacearea (areas may be estimated).
(b) Particlesoategori~ed by size and count per 1).1s~re maker of significantsurface area (areas may be estimated). Lisiit8may a180 IM9specified on a per item basis rathex than par unit area, volume, orIMBS . PAC meesured as total particle projected area divided bytotal significant surface area. M/R in milligrams per swrecentimeter of significant surface area (areas may be estisnted).Volatile condensable material (VCM) from bulk material may bereported in milligrams per 0.1 square meter of significant area orper unit mass of bulk material.
(c) ~. Particles categorized by size and count perunit volume in accordance with ARP 598 or demonstrated equivalent.NVR measured in mass per unit volume. Turbidity is characterizedby Nephelometric Turbidity Units (NTU).
(d) -. Particles categorized bysize distribution inunits of count per unit volume.
13 ‘“
MIL-&l’D-1246C
5.1.2
5.1.2.1 ~ Direct xmasurement is theanalysis of part of the surface, liquid or gas of interest.Exqles are counting particles on the surface ~ using amicroscope or performing NVR analysia on a san@e of liquid ofinterest. Direct measurement of particles or NVR in situ, is themost accurate technique, although limited methods exist. Arequirement for direct, non-contact microscopic examination ofparticles on a surface is ohly feasible if the surface qticalproperties allow such examination, Alternative surface w fluidmeasurement techniques are acceptable, having damnstzatedequivalence.
5.1.2.2 Extractive san@ing of surfaces,liqu~clnwr W- fur viW-3zne meeewawmnt &e tJaeJmos&.nidelYUa.edapproach for particle and NVR cleanliness determination. Samplecollection techniques and measurement methods to determinecleanliness shall be accomplished wing the ASIllprocedures(partial listiti~) shown in table XIX, m by demonecratedequivalents. Extractive sampling is the analysis of a medium otherthan that of interest. ~~es are co~ti~ ~~ticl- On t-ethat has been used to renmve particles from a surface of interemtin accordance with A#IM 4U216 or d~nstrtied equivalent; oranalyzing liquid used to flush a surface of interest. J@ccessfulextractive s~ling requir*8 a technique of kncmm extractionefficiency fprasably CIOSe to 100 percent efficiency) . Multi@eextra~tione should.pmduce conc~ntzations that approach those ofthe extraction fluid itself; otherwise, complete removal has notoccurred or contaminants generation may be occurring or both.
ti some cases the medium of interest is gas or liquid ctingfrom contact with a Possibly eontesdnated curfaca. This is directmeasur~t of the &a bY llquiU, and extreetive sampling o~ thesurface. Because of uncertainty in sen@$ng efficiency, directsanpling is preferable to extractive sampling.
S.1.2.3 Indirect witness san@es are thethird and least accutate method for particles and NVR cleanlinessdetermination, but ~ be the only method available when directscanning or physical aqling of a product is not faasiblc. -emethod for NVR witness samples is documented in AST14 E1234 andASTM E1235. Particles witness samples shall take any form whichrepresents the actual condition, and measurement methods shallfollow the same requirements specified above.
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MIL-STD-1246C
TABLE III.
Sampling Techniques Measurement Techniques
AS’114F51AS’IM F303 ASTM F311
Surfaces ASTM F306 ASIM F312AS’JU E1216 M’XS4 F331AS’IM E1234 ASTM E1235
ASII14F302 ASTM F311Liquids Asm F303 ASTM F312
ASTM F1094 AS~ F331ARP 598
ASTM F25 I&I’M F25AS’IM F50 ASTM F50
Gases ASTM F307 ASIM F312ASZZ9 F318 AS~ F331A31U F327 ARP 743
specifying particulate levels on a surface is expressed as percentarea coverage (PAC). particle area may be directly measured usingimage analysis or dther techniques. otherwise, partielw sizing andcounting must be perfcmaad and the values converted to a PAC value.Table IV provides the conversion formula and is based on a samplesize of 0.1 square meter. Other Xssible methods for P= includeobscuration or light scattering, after having demonstratedequivalence with actual measured projected areas.
5.1.2.5 s In somecases, it is desirable to specify a particle count limit in amanner different fzxm that shown in table 1. As examples, onemight specify total count per unit extent for particles in aspecified size range, or the maximum quantity of particles smallerthan 1 micrometer, or the mximum quantity of particles measuring10 to 50 micr~ters, or xMximum quantity of particles larger than20 micrometers, or specification of another size distributionlimit.
15
MIL-STD-1246C
Another approach would be to specify certain particles typesto be limited. For example, those that contain sodium or aremagnetic. Alternet ive particle count mpecif icationa shall identifywhat is to be measured, how it is to be measure& and defi= t~limit in terms of count per unit extent.
5.1.2.6 P Volatile condensablenaterial (lKM) is determined from a preconditioned sample subjectedto a r?pecified teuqxmature with the VCM collected at a lowerspecified temperature. CZeanlines$ requirements are specified asCVCM (see 4.2) when tested in accordance with ASTM E595 and as VCMwhen tested by methods other than ASl%$E595.
TABLE 7V.
Particle Particles x Coefficient = % Area
Size Range Per 0.1 x? Coverage
>1”10 J.un ~ x 1.737 x 10-8 =
>10-25 ~ x 1.528 X 10-7 =
>25-50 ~ x 7.078 x 10-’ = -
>50-100 ~ x 2.43s x 10-6 =
>1$0”150 * x S.1$6 X 1~6 =
>150-250 pm x 7.404 x 10-6 -
>250-509 @ x 6.522 X 10-6 =
>500-750 pm v 1.048 x 10+ =
> 750 pm x 1.922 X 10-5 =
(Sum all values to obtain total percent coverage area.)
1/ Value may be -timated ~ <iplying counts within the10-25 pm range for count in the l-10~ range by 3.24. These are~zial coefficients based on the work of Ma, Fong, and Lee,(see 6.4).
16
MIL-STD-1246C
5.1.2.7 ~ Turbidity is measured by either thereduction in transmission or the increase in scattering of light byparticles in a liquid. The units of measurement are NephelometricTurbidity Units (NTUS).
5.2 ~ ~f data.
Data shall be analyzedwith statistical techniques, such as those listed below so as toderive 95 percent confidence limits (-e 6.3).
5.2.1 ~. . .
If only one sample has been obtained and it has a count of N (for N> 50) , then the 95 percent confidence limits for the true (~how)mean count can be estimated from the expression Upper 95% limit =
(N+l.92) + (1.960 times the square root of [N + 1.01), and Lower958 limit = (N+l.92) - (1.960 times the square mot of [N + 1.0]).MS expression is an a9prcw@nWZon when N = 1 to 50” For a countofN= O, the limits are O to 3.7.
5.2.2 Let the number of measurementsbe n, with n > 1. Let the values of the measurements be x(1),X(2), ....x(n). The san@e mean is the sum of the x values dividedby the number of measurements taken:M= Z x/n. The sample mean is the best estimate of the true mean.
The sample standard deviation is approximately the square rootof the mean of the squared differences between the s~-e mean andthe readings:s = square root [~ (X-M)2 /(n-l)].
The upper 95 percent confidence limit for the mean isM + (t)(s)/square root (n) and the lower 95* confidence limit forthe mean is M - (t)(s)/square root(n), where t is obtainable fromtables of Student’s t in most statistics texts. Form > 10, t isabout 1.65. The quantity s/square root(n) is known as the standarderror of the mean.
5.2.3 For particle counts, N,the transformation y = square root(N) will produce a varitile~ Y,that often has a distribution that is more nearly no-l (Gaussian)than is the distrl~tion of-l?.“For particle counts ‘or mncentmtionvalues that have a negligible fraction of values that equal zero.~the transformation z = 109 (x) will W@Jce avariable, z, that often has a distri~tion tht iS ~re nearlYno-l (Gaussian) than the distribution of x is. Suchtransformation can improve the accuracy of the Student’s tanalysis.
5.2.4 ~ If the time interval or the spatialinterval over which n samples are taken has a uniform
17
MIL-STD-1246C
concentration except for random deviations about the meanconcentration, then the difference between one mean of n samples andanother mean of n samples would be approximately proportional to 1/square root (n). If there are systematic differences ofconcentration over the time interval or spatial internal, thendifferences between means will often be inversely proportional toPOW rs of n that are larger than suuare root(n), sach as I/n or
9I/n . Comparing the means of two or nume sasplee of size n can aidin determining how many san@es are needed to get a desiredconfidence limit magnitude.
5.3 As a minimum, the following informationis normally recorded:
[a)
(b)
(c)
(d)
(e)
(f)
(9)
(h)
(i)
(j)
(k)
(1)
If it is
Item name and description
Person &oing s~ling/Analyst
Sample size
Number of samples
Identification of replicate s~les
LoCat ion
Date/time
Operating conditions
-i mmment
Equipment
Method
Results.
desired to display the data graphically, figure
.--
1 indicatesthe levels of table 1 plottul on axes of log of the count versus the~- of the logarithm of the particle size in mic~ters. Figure1 1s anroximata and should not be used to define the requirementsgiven in table X.
5.4 ~ ~. .
1Based on the specification of product cleanliness, a
contamination control program shall be implemented. The progr~shall encompass, but is not limited to, the following:
. ,-
18
MIL-sT’D-1246C
5.4.1 ~ The cleanliness level of theproduct and its sensitivity to contamination shall be determined bv
I
the product design activity unless otherwise specified.Contamination limits are to be prescribed by design drawings orspecifications consistent with the product requirements. When theproduct design activity cannot predetermine the cleanliness level,a proysed method for determining this level through investigation,experimentation or assessment shall be included. A product designreview in terms of contamination sensitivity shall be conducted tofinalize requirements.
5.4.2 The designatedpoint of contact with the authority to insure that the productmeets design criteria and specification requirements shall describethe organizations responsible for implementation of the program.
5.4.3 ~ Procwns m cOntrOISapplicable to the product, at each state of manufacture orprocessing, including parts, components, assemblies, andmaterials that will affect the cleanliness of the product, shallbe Specified. Theqe processes and controls shall be addressedaccording to the requirements of the contamination controlprogram.
5.4.4 ~ Requirements for th6--cleanliness, environmental controls, operation, certification, anddata tracking for facilities used to fulfill the requirements ofthis standard shall be specified in the plan. Methods and practicesfor control of particulate and nonparticulate contaminants,t~rature, relative humidity, or other conditions (see 6.3)critical to the product shall be addressed. Where specification ofairborne particulate concentration is required, the specificationshall be in accordance with FED-STD-209.
5.4.5 ~ . A method shall be determined fori-sing contamination control requirements on sub-tiercontractors.
5.4.6 ~ Calibration procedures andfrequencies for instrumen ts and equipment used directly orindirectly for cleanliness verification shall be addressed.
5.4.7 ~tv c~ Quality centrol procedures and recordkeeping shall be addressed “to ensure surveillance and compliance.
19
I
MIL-STD-1246C
I
I
5.4.8 Materials and methods for productprotection shall be addressed :0 maintain the required productcleanliness level.
5.4.9 ESZXUUW. Personnel training, motivation, controlmethods, or other considerations (see 6.3) shall be addressed.
.-.
MIL-STD-1246C
6. NOTES .
(This section contains information of a generalnature that may be helpful, but is not ~n&toW.)
6.1 ~. This standard is intended
or explanatory
to be used as abasis and a uniform method for establishing product cleanliness andcontamination control.
6.2 ~ When this standard is used inacquisition, the issue of the DODISS to be applicable to thissolicitation must be cited in the solicitatim (see 2.1.1 and 2.2).
6.3 ~.
The following sources have beenfound useful in the conduct of contamination control programs:
(a) Institute of EnvironmentalReconwnended Practices, ConttinationNorthwest Highway, Mount Prospect IL
Sciences, Handbook ofControl Division, 940 East
(b) Wilson E.B.jr., “m Introduction to Scientific Researchm,McGraw, NY, 1952 .*.
(c) Box G.E.P., Hunter W.G., Hunter J.S., Statistics forExperimenters, Wiley, NY, 1978
(d) ASTM Standards for Cleanrooms, 1993
(e) Ma, P.T., Fong, M.C., and Lee, A.L., ‘Surface particleObscuration and BRDF Predictions”, SPIE vol. 1165, Scatter fr-@tical Components, 1989.
21
MIL-STD-1246C
6.4
6.5not usedprevious
contaminantLevel, cleanMaterial, collected, condensable, volatileMicrometerResidue, non-volatileParticleSurface, significant
Marginal notations are
in this revisim to identify changes with respect to theissue due to the extensiveness of the changes.
Custodians:--MINavy - YDAir Force - 99DLA - GS
Review activities:m- AV, AT, GL, AL, ARNavy-AsAir Force - 70, 711 84
Preparing activity:--~
project NO. 3694-0034.. .
User activities:AIW:~~HNavyAir Force’- 79DLA - ES
22
MIL-STD-1246C
APPENDIX
CLEANING METHODS AND MATERIALS
10. GENEIUL
10.1 -. The purpose ofnon-mandatozy supplemental guidancedocuments relating to contaminationof cleaning processes and equipmentdesign of items, their constructive
this appendix is to providefor the preparation ofcuntrol programs. The selectionis strongly influenced by thematerial and surface
treatments, and the fabrication process which produce them.Early consideration of the need to clean can result in design,materials and process changes which do not decrease utility butresult in items which can be more effectively dleaned at a lowerCost ● Included in the considerations should be the healtht saf@tYand environmental ~acts of the total xmmufacturing and cleaningpxocess . Many materials may be subject to local, state or federalrntatutory contxel effecting use and disposal.
20. APPLICABLE DKUMENTS
20 ● 1 ~ ~t wPli-le
20.2 ~t The following documentsform a part of this standard to the extent specified herein.Unless othemise specified, the isau.eof the documents which areDoD adopted are those listed in the iamue of the DODXS~-Ated hthe solicitation. Unless otherwise apacified, the issues ofdocuments not listed in the DODIS$ are the iw!$uesof tha doc~tscited in the solicitation (ace tO.2).
AKERXCAN SOCIETY FOR TESTING AND MATERIALS (ASTM)
ASTM A380 - Stan rd Practice for Cleaning and?Dmca ing of Stainless Steel Parts,
Equi_t, and Systems
30. DEFINITIONS. This section is not applicable to thisappendix.
40. GENERAL REQUI~S.
40.1
40.1.1 This method is use to achieve visiblyclean articles. Gross clea~ing removes contaminants such as weldscale, heat treat scale, corrosion, oxide films, oils, grease, shopsoil, fuel, and carbon deposits. The cleanliness level achieved bygross cleaning does not normally require verification beyond visualinspection. (Wipe test$ water break test, ultraviolet inspection,special light and mirrors, are considered aids to visualinspection.) Gross cleaning is considered a normal shop process andusually does not require especially clean conditions beyondaccepted good practice.
23
MIL-STD-1246C
APPENDIX
40.1.1.1 The following types ofcleaners, or their equivalents, may be used for removing grossforms of contamination. NOTE: Chemical cleaning agents must beccxupatible to prevent excessive attack or latent degradation.
40.1.1.1.1 U r~ ● Acid cleaners are used to removecontamination, such as, weld scale, corrosion and oxide films notremovable ~ other solutions. _les are nitric acid, inhibitedhydrochloric acid, inhibited sulfuric acid, inhibited phosphoricacid, mixed acid deoxidizers and alcoholic-phosphoric acid.
40.1.1.1.2 Alkaline cleaners are used forthe remval of organic and inorganic eonttination. such as grease,stip soil, scale and 8oluble metal oxides. Alkaline cleanersdissolve (etch) certain metals such as aluminum or zinc. Examplesare alkaline rust strippers, heavy duty alkaline cleaners, moltenalkalies, alkali, alMli””’’wTth””’filtYaZeor phmphate. ~~
40.1.1.1.3 These cleaners areused for the removal of organic and inorganic contamination such asoilm, fats, shop soil and grease. elms aro,inhibited alkalinecleaners (mild alkaline cleaners) , S-PS, emul~lon cleaners~aurfactants, and detergents.
40 ● ~ .1.1 ● & ~ ~ese ‘L-ne- are -“dto ~e forms of organic contamination such as oils, Qmase andhydrocarbon fuels. Exax@es are alcohol and acetone. Class I OzoneDeplating Chemicals (ODCS) and Class xx OCDS as defined inparagraph 40.1.2.2.9. of this st=rdard are -luded from uss AS anorganic solvent cleaner.
40.1.1.1.5 These cleaners areused t,oremove the residue material left by cleaning solutions andas final flushing or rinsing medium.
40.1.1.1.6. .~s These
cleaners are used as a supplementa~ treatment to acid, alkalineand mechanical cleaning. The neutralizing and passivating solutionsprevent corrosion and acid etching. Examples are nitrate,phosphate, alkali with nitrate or phosphate to neutralize; nitricacid or nitric acid solutions to passivate.
40.1.1.1 ●7 ~ This Proce=s r-v~scontamination by abrasive action, and is only used when physicaldamage to the items being cleaned will not occur. Examples ofmechanical cleaning are wire brushing, shot blasting (wet and dv),grinding, sand blasting (wet or dxy), the use of aldn~ oxide(abrasive coated papers and cloths and related methods. NOTE:Mechanical cleaning often leaves foreign depoeits which may requireadditional cleaning for their removal. Compatibility of dissimilarmaterials, especially metals, is an important consideration whenselecting a mechanical cleaning method.
24
APPENDIX
40.1.1.1.8 Table V contains therecommended gross cleaning processes and sequences.
40.1;2 This method is used to achieve alevel of product cleanliness greater than the level normallydetected by visual neans. Articles should be visibly clean priorto precision cleaning. Precision cleaning is performed in acontrolled environment, and is intended to remove particles, films,biological forzne, fibers and other fokms of’contaminants that areusually not visible, but which could degra~ the product orprocess. The level of pre~ision cleanliness should be verified andevidence of inspection and acceptance provided. Precision c!leanedar~icles should repackaged i~diately after verification ofcleanliest, or suitably protected prior to leaving the controlledenvironment.
40.1.2.1 ~. ,
Precisioqcleaning solutions or material didtildfretreact with, combine with,etch or otherwise cause ixmediate or latenC degradation of the itembeing cleaned. ~ecision cloazaing flti&-AmAd be filtered andcontrolled. Their cleanliness level should be verified ●s bein’gsufficient to achieve the epecified product cleanliness. Selectionof precieion cleaning fluid must take into consideration the natureof the contaminant to be removed, reactivity of the item beingcleaned, health, safety an@ enviro-tal ~s@~ of th.~fluid ~ddicposul of waste, including spent cleaning fluid. Cont*lteehndogy to~ither ocmkain&be ~eeisiomr2Mning fluid, reuseit, or.both must be provided a$ health, safety, ‘and environmentalhazards dictate. Exm@es of Mterials cosawn ly used for cleaninginclude abrasive eolide, air, carbon diomide snow or pellets8deionized water, detergent, surfactant, inert use and organicsolvents.
40.1.2.2 ~ s Equipmentand various methodB suitable for precision cleaning are available.TM appropriate process and equipment should be selected on thebasis of product configuration, compatibility with cleaning fluids,type and quantity of contaminants, desired cleanliness level,economics, safety and environmental risks. The following equipmentand methods are available alone or in combination when selectingthe appropria~e process for a particular product.
,.
25
MIL-sTD-1246C
APPENDIX
TABLE V. 1/
Material Surface Gross Cleaning Processes 3/Condition
NEc oRq ALx DET ACD NEu DIW DRY
Bar8 ormachined, free x x x . xof heatoxidation
Aluminum Conversion orx x x x
— ~ ~ — — — — —Weld scale,
x x x x x
4Bare or machirikd, ‘“ ~
x x x x
Copper/bressi Ccmwrsilon orbronze choAoal film. x x x x
Welx’ x x x x.-.
Stainless , Fmee of s~ale x x x x- x xsteel 2/ Weld scale t
x x x x x, x x
Carbon stealWeld scale,corrosion, orheat oxidation x x x x x. x x
Non-metallxGpaz”ts, As rocaived x x x
Olast-rs
Electroplatedparts anddissimilar AS received x x x xmetals
1/ ‘X” denotes a recoxmnended process for the surface conditionindicated, and will normally be accomplished in consecutive orderfrom left to right.z/ AS’!M-A380 describes in detail recommended methods for descalingand cleaning stainless steel.
26
MIL-sTD-1246C
APPENDIX
TABLE V..es . ~d
2/ Cleaning processes defined:
MEc =ORG =ALK =DET =ACD =NEu =DIW =DRY =
Mechanical descale /cleanOrganic solvent degreaseAlkaline clean and tap water rinseDetergent clean and tap water rinseAcid pickle and tap water rinseNeutralize and passivate and tap water rinseDeionized water rinseDrying
40.1.2.2.1 The item is washed in suitableclean detergent/waCer solution or solvent, followed by a successionvf “rinses. Uo-LlyV mechanical action such as agitation orbrushing is necessary LO assure removal of all cont~nants.
40.1.2.2.2 ~ Spray cleaning may be divided inthree pressure ranges in order Of overall effectiveness:
(a) High pressure - greater than 10,342 kilopascals (kPa)(1500 p.s.i). High pressure water cleaning should not includedetergents as foam formation reduces cleaning efficiency.Precision fixtures are also required but can be effectiye atcleaning coqplex geometries including threaded, blind and t&oughholes .
(b) Intermediate preaaure - 6g0 to’10,342 kPa [100-1S00p.s.i.). Intermediate pressure is lower in efficiency than highpressure spray cleaning. Addition of low foaming surfactant cani~rove efficiency in certain cases.
(c) LOW pressure - 1.8s than 690 kpa (1OO P.S. i. ) . pressuresat this level are relatively ineffective as a primazy cleaningprocess . However, they are very effective at rinsing awaycontaminant= which has been loosened by a previous C1-ninUprocess, such as ultrasonic cleening.
40.1.2 .2.3 ~.
Sonic cleaning may be divided intotwo general ranges based on frequency. Each range exhibits uniquecleaning characteristic@.
(a) Ultrasonic cleaning - 15 to 100 kHz.Ultrasonic cleaning provides nondirectional cleaning suitable forcomplex geometries. Cleaning efficiency is severely limited inhOle6 and in eimilarly tight geometries. Surface damage may occuras a result of cavitation erosion.
27
.—
MIL-STD-1246C
APPENDIX
(b) Megasonic cleaning - Frequencies greater than 100 kHz.This method produces highly directional cleaning suitable forsimple geometries. Megasonic cleaning tends to produce lesssurface erosion than ultrasonic cleaning.
40.1.2.2.4 The item to be clean is exposed toheated solvent vapors which condense on the part and wash awaycontaminants. This is effective for soluble contaminants and isused as a d~ing method. However, the method is relativelyineffective for small particles.
d~.1.a.z.s ~. The item to be cleaned is flushedwith a suitable cleaning solution. me item is agitated thoroughlyto wash 812 surfaces and the solution is drained away.
40.1.2.2.6 ~.
This method is usedprincipally after ’’tihdt?iet”elWam!hlgxhod’has &used. Xn -thismethod, the item being cleaned is rinsed white turn~ng slawly. Theitem is then accelerated to higher speed in revolutions per minute(RPM). Thq,hi h an~lar velocity accelerates Ghe liquid, removing
1!particles by s ‘ear stiess. The rin8ing Iiquitl is also renwod,thus drying the part.
40.1.2,2.7 ‘ g Zhe itemto be cleaned is immrsed in a solution specifically forswhted or●mrgizad to remove the base matarldl of thb part. Fi%fwring theitem is critical for effective treatment. The dissolution of thebase material smooths the surface and releases contaminantsesbedded on tk surface of the part. ‘heatmant tiths =st befiltered and processing must be followed by rinsing with deionizedwater to remove chemical residue.
~o.1.a.a.a ~. ~nsideration should be given toother cleaning methods not descrilxd previously such as, a~onsnow, supercritical fluids, plasma, W-ozone.
40.1.2 .2.9 Substances classifiedas a Class I Ozone Depleting Substance by the Clean Air ActAmendment of 1990, and certain Class TZ ozone depleting substances,should not be given consideration or recoiranendationby thisdocument. Class I mb$tances te be awsided are chlorofluorocarbons(~lKs), carbon tetrachloricle, msthyl chlerofozmb methyl bromib,and hydrobromofluorocarbons (HBFCS). ClaSS II s@stances to ~avoided are hydrochlorofluorocarbons (HCFCS) 22, 141b, and 142b.
40.1.2.3. . .~ Disassembly, cleaning,
raass~ly, in-process handling, packaging and other operationsinvolved in cleaning should be conducted in a manner to preservecritical tolerances, finishes, calibration or other sensitiveattributes of the product. Mequate tooling, fixtures, handlingdevices and product protection should be provided. Writteninstructions for sensitive or critical activities should beprovided.
28
—
MIL-sTD-1246C
APPENDIX50. PROTECTION
50.1 ~. .
All precision cleaned itemsshould be provided with cleanliness protection prior to leaving thecontrolled environment.
50.2 ~ The precision clean packagingshould maintain the cleanliness level specified for the product.
50.3 ~. Storerooms or inventory control areas shouldprovide adequate protection to the package and the product for theintended storage period.
.-.
29
MIL-STD-1246C
APPENDIX
60. INSPECTION
(
I
60.1 . Inspection of precision cleaned andpackaged products should be performed as required on a regular orcyclic basis to assure continued maintenance of the integrity ofthe package and the item. The following criteria should constitutecause for rejection of the precision cleaned and packaged item:
a) Identification label or deoal mimsing, broken, illegibleor incomplete.
b) Tamper-proof seal missing, broken or incorrectly applied.
Improper seal, open seal or closure, lifted tape, etcd)Appar~~tly daxmged (including pinholes and the like) or violatedpackage or closure.
e) Visibly entrapped moisture (or a change in humidityindicator) or other unwanted material.
f) Any apparent defect that may interfere with the properfunction or use of the item.
60.1.1 If it is necessaxy to break aclosure or open a package for inspection, the item should be openedin a controlled environment and repackaged to the same conditionsas the original. .=.
60.1.2Inspection requiring opening of a package or closure shou~d be
nf a
limited to a minimum of occurrences consistent with good practice.
60.1.3~. . . To assure traceability of contamination
Bourcea, a record should be maintained of all incidents of openingor closure of the packages. The record should show the date,responsible person, the reason for opening the package or closure,and the disposition of the product.
60.2 ~ When this standard is used inacquisition, the issue of the ~DISS to be applicable to thissolicitation must be cited in the solicitation (see 2.1.1 and 2.2).
30
—
STANDARDIZAnON DOCUMEW IMPROVEMEW PROPOSAL
tNmumoNS
1. Thepfeparimlec?hltymustcompleteblocks1,2,3,●d U.@ block1,both the documentnumberandrevisionletter shouldbegiven.
2. ~ submitterof thisformmustcompleteblocks4;S,6,and7. -
3. Theprepbg ●ctivitymust provide ● rurplywithin 30daysfromreceiptof theform. -“ ~
NOTE: lhisfOrmnMyti* U** -d=~ dmnents, nor to raquestwaken, of darific~tio~ofrequhnents on currant contractL Commentssubmittedon thisformdo ngtconsdtuteor implyRuthorition towiive any portion oftherefenmceddocument(s)or to ●mend Cmtracwal reqdrementS
I
1. DOUJMW NUMBER 2. DoamENTMTE(Ymska3)
1. DOCUMENT TITLEProduct Cleanliness Levels and Contamination Control Prwram ‘
-
k NAnRSO~M- WwpVa@-r d~~~, ~~A--~-mU=d
---
.
. WON fOR RECOMMENDA-
●REPARING A~
. NAME b.TELEWONE & -Q -)
U.S. Army M!sst7eKommnd(1)commercial (2) AuTovw
205-876-6980 DSN 746-6980AOORESS (Include ZIP Cafe) IF YOU DO NOT RECEWE A REPLY WTHIN 4S DAYS, CONTA~:
Gxmnander, U.S.Army Missfle Command, oebw ou~lity •n~ st~nd~rdiz~tion Offk?
llJ!&J1’?!&!!?i~E2D-&_5203 LeebIr9 Pike. Sdte 1403, Falls ChWCL VA 2204 I -3466Telephone t703)7S6-2340 AUTOVON 289-2340
Ml. !w!Y!?-t69fi
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