1、Designation: E 1548 03Standard Practice forPreparation of Aerospace Contamination Control Plans1This standard is issued under the fixed designation E 1548; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 is intended to assist in the preparation offormal plans for contamination control, especially of aerospacecritical sur
3、faces. Requirements may be established at thesystems level, either by the customer or the systems integrator,or at the subsystem level. Subsystem requirements may beimposed by the responsible subsystem supplier or they may beflowed down from the systems organization (4.7). The extentof detail and le
4、vel of cleanliness required can vary with theparticular application and type of hardware being built, but allaspects of contamination control must be included in a finalplan. Therefore, each of the following elements must beconsidered for inclusion in a contamination control plan(CCP):1.1.1 Cleanlin
5、ess requirements for deliverable hardwareaddressing particulate, molecular, or biological contaminantsor combination thereof. Specify contamination limits and anybudget allocations.1.1.2 Implementation plans to achieve, verify, and maintainthe specified cleanliness requirements. Specify material and
6、process controls, cleaning techniques, verification tests, pro-tection and prevention plans, transportation controls, andcorrective action for discrepancies.1.1.3 Environmental controls including clean facilities tobe used, facility maintenance, and monitoring schedule.1.1.4 Personnel and operationa
7、l controls including operat-ing procedures, restrictions, training, motivation, and organi-zational responsibilities including the organization or indi-vidual for implementation and verification of the CCP.2. Referenced Documents2.1 ASTM Standards:E 595 Test Method for Total Mass Loss and CollectedV
8、olatile Condensable Materials from Outgassing in aVacuum Environment2E 1216 Practice for Sampling for Surface Particulate Con-tamination by Tape Lift2E 1235 Test Method for Gravimetric Determination of Non-volatile Residue (NVR) in Environmentally ControlledAreas for Spacecraft2E 1549 Specification
9、for ESD Controlled Garments Re-quired in Cleanrooms and Controlled Environments forSpacecraft for Non-Hazardous and Hazardous Operations2E 1559 Test Method for Contamination Outgassing Charac-teristics of Spacecraft Materials2E 2042 Practice for Cleaning and Maintaining ControlledAreas and Clean Roo
10、ms2E 2217 Practice for Design and Construction of AerospaceCleanrooms and Contamination Controlled Areas2F 50 Practice for Continuous Sizing and Counting of Air-borne Particles in Dust-Controlled Areas and Clean RoomsUsing Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles2F
11、 303 Practices for Sampling Aerospace Fluids from Com-ponents2F 312 Test Methods for Microscopical Sizing and CountingParticles from Aerospace Fluids on Membrane Filters32.2 Government Standards:FED-STD-209E Airborne Particulate Cleanliness Classes inCleanrooms and Clean Zones4,5USAF Tech Order 00-2
12、5-203 Contamination Control ofAerospace Facilities, U.S. Air Force42.3 International Standards:ISO 14644-1 Cleanrooms and Associated Controlled Envi-ronments, Classification of Air Cleanliness6ISO 14644-2 Cleanrooms and Associated ControlledEnvironmentsCleanliness Levels6ISO 15388 Space SystemsConta
13、mination and CleanlinessControl62.4 IEST Standards:IEST-STD-CC1246D Product Cleanliness Levels and Con-tamination Control Program7NOTE 1The Institute of Environmental Sciences has several Recom-mended Practices which may also be useful in the preparation of a CCP.1This practice is under the jurisdic
14、tion of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition approved May 10, 2003. Published June 2003. Originallyapproved in 1993. Last previous edition approved in 1998 as F 1548 93 (1998
15、).2Annual Book of ASTM Standards, Vol 15.03.3Annual Book of ASTM Standards, Vol 14.02.4Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.5FED-STD-209 has been superceded by ISO 14644-1 and -2. It may continue tobe used i
16、f mutually agreed to by customer and supplier.6Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.7Available from Institute of Environmental Sciences and Technology (IEST),5005 Newport Dr., Suite 506, Rolling Meadows, IL 60008-3841.1Copyright AS
17、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions:3.1.1 bidirectional reflectance distribution function(BRDF)the scattering properties of light reflected off sur-faces, expressed as the ratio of differential outputs of
18、 radiancedivided by differential inputs of radiance. Surface contami-nants scatter the incident radiation in all directions and withvariable intensities; BRDF is a method to quantify the spatialdistribution of the scattered energy.3.1.2 biological contaminationliving material such asalgae, bacteria,
19、 fungus, and so forth, which is capable ofreproducing, thus being an increasing contaminant source.3.1.3 budget allocationthe itemized summary of contami-nation accumulation for a given critical hardware item distrib-uted over all phases from manufacture through end of perfor-mance lifetime.3.1.4 cl
20、eanrooman environmentally conditioned areawhere temperature, humidity, and airborne contaminants arecontrolled by design and operation. High Efficiency ParticulateAir (HEPA) filters or better are usually required to achieve theair cleanliness level. Air particulate cleanliness is classified inaccord
21、ance with ISO 14644-1.3.1.4.1 as-built cleanrooma cleanroom that is completeand ready for operation, with all services connected andfunctional, but without equipment or operating personnel in thecleanroom.3.1.4.2 at-rest cleanrooma cleanroom that is completeand ready for operation, with all services
22、 connected andfunctional, and with equipment installed and operable, asspecified but without operating personnel in the cleanroom.3.1.4.3 operational cleanrooma cleanroom in normal op-eration, with all services functioning and with equipment andpersonnel, if applicable, present and performing their
23、normalwork functions in the cleanroom.NOTE 2For batch operations, specific conditions and requirementsshould be noted for monitoring and control.3.1.5 clean zonea defined space in which the concentra-tion of airborne particles is controlled to meet a specifiedairborne particulate cleanliness class.3
24、.1.6 controlled areaan area which does not require ahigh degree of temperature and humidity control but a semi-clean atmosphere is desired. Air conditioning is standardcommercial design except that filtration is rated to 80-85 % for1.0 micrometer (m) and larger particles to control airbornecontamina
25、nts. These areas shall not exceed the airborne par-ticle concentration of Class 8.5 (FED-STD-209E Class300,000) at 0.5 m and Class 8 (Class 100,000) at 5.0 m perISO 14644-1 (FED-STD-209E). Reference USAF Tech Order00-25-203.3.1.7 facilitythe total real property required to accomplishthe environmenta
26、l control and operation of cleanrooms, cleanzones, and controlled areas as well as administrative andpersonnel support.NOTE 3This includes the cleanroom proper, air locks, change rooms,parts cleaning, storage, HVAC equipment, offices, and so forth.3.1.8 HVACHeating, Ventilating, and Air Conditioning
27、.3.1.9 image analysisthe measurement of size, shape,number, position, orientation, brightness, and other parametersof small objects using the combination of an autofocusingmicroscope, an imaging sensor, and a dedicated computersystem. Can be used to perform particle counts or measureparticle dimensi
28、ons automatically, with far greater accuracythan manual techniques.3.1.10 molecular contaminationnonparticulate matter inthe form of droplets or thin films which adversely affectscomponent or system performance.3.1.11 nonvolatile residue (NVR)soluble material remain-ing after evaporation of a filter
29、ed volatile fluid or precipitatefrom a gas phase, usually reported in milligrams per unit area(or volume).3.1.12 particulate contaminationsmall discrete mass ofsolid matter, usually measured in micrometers (m), whichadversely affects component or system performance.3.1.13 precision cleaningcleaning
30、of hardware surfacesby approved engineering methods to meet specific cleanlinesscriteria.3.1.14 visibly cleanabsence of particulate or molecularcontaminants when viewed from a specified distance withnormal (or corrected to normal) vision with a specifiedillumination level.4. Contents of CCP4.1 Gener
31、al Items and Information:4.1.1 All CCPs shall include an introduction or scopespecifying the contamination-sensitive component(s) or sys-tem(s) being addressed, a list of applicable documents, and alist of definitions including any acronyms and abbreviationsused in the document.4.1.2 The level of de
32、tail required and the nature and extentof controls needed depends upon a number of factors. Thesystems organization or systems integrator has a better over-view of contamination limitations, sensitivity of specific com-ponents and hardware, and total mission requirements thansub-tier suppliers. Cont
33、amination limits for total systems arethe primary responsibility of the systems organization. Finalcontamination limits at delivery of the integrated system and atend of life should be established by agreement between thepurchaser and systems supplier. Each supplier is responsiblefor defining and co
34、ntrolling the contamination level of theparticular hardware being supplied, with the approval of thesystems organization, in addition to requirements levied by thesystems integrator.4.1.3 The buyer and seller should agree on the contents andimplementation of the CCP before any parts are processedbey
35、ond the first cleaning or inspection point. Suppliers ofsubsystems and components should prepare ContaminationControl Plans so that the functional requirements of thehardware are protected. If a subsystem is particularly sensitiveto contamination, there must be adequate controls and compli-ance with
36、 system contamination requirements. Examples ofsensitive subsystems include optical or non-optical sensors,gyros, thermal control systems, liquid propellant systems, andcryogenic devices.4.1.4 Some subsystems are relatively insensitive to con-tamination. These should be identified and justifications
37、 givenE1548032for limited contamination control efforts. Even if a particularsubsystem or hardware is not sensitive to contamination it mustnot be a source of contamination for other, more sensitive orcritical hardware. Also it is important that system performanceor contamination allowables not be d
38、egraded by contaminantsemanating from contamination tolerant hardware.4.2 Cleanliness Requirements:4.2.1 Cleanliness requirements must be specified for deliv-erable components or systems addressing particulate, molecu-lar, or biological contaminants, or combination thereof. Pri-mary responsibility f
39、or contamination control remains with thehardware or subsystem supplier. Levels of control and allow-able types and quantities of contaminants shall be as agreed bythe supplier and systems organization when applicable. Specifycontamination limits and the point in time when the require-ment must be v
40、erified (for example, IEST-STD-CC1246DLevel XXX after manufacture, or X.XX % area coverage atdelivery to integration contractor). Define any budget alloca-tions if different cleanliness levels are to be verified at differenttime intervals. Also identify whether the requirement is criticalto the hard
41、ware performance or is necessary to protect othercritical hardware.4.2.2 Define how the cleanliness requirements will be im-posed in operation; identify the relevant documents such asdrawings, process documents, inspection procedures, testplans, manufacturing flow diagrams, acceptance plans, and sof
42、orth.4.3 Implementation Plan:4.3.1 Attainment of Cleanliness RequirementsDescribethe means for achieving the specified cleanliness requirements.This focuses on (1) selection of low outgassing, low shedding,and low particle generating raw materials, (2) design featuresto protect against contamination
43、 such as filters, cold traps,baffles, debris shields, and so forth, (3) cleaning and processingtechniques that will effectively remove contaminants fromsurfaces, and (4) facilities to be used for various operationssuch as cleanrooms of a specified class or controlled areas.Where pre-launch or post-l
44、aunch cleaning operations areplanned, these shall be described here also. These elementsmay be contained in separate documents, but shall all beresponsive to the requirements and cross-referenced in theCCP. ISO 15388 also contains recommendations on contami-nation control requirements and guidelines
45、 for establishingcontamination control plans.4.3.2 Verification of Cleanliness RequirementsIdentifythe techniques planned to verify compliance with the cleanli-ness requirements, including particulate, molecular, or biologi-cal contaminants, or combination thereof. Rationale for use ofwitness sample
46、s versus direct examination or solvent extrac-tion techniques should be included. Specify method of directsampling, such as tape-lift per Practice E 1216, spray flush perPractices E 303, and so forth, and specify method of testing,such as microscope counts per Test Methods F 312, outgassingper Test
47、Method E 595, Test Method E 1559 to evaluateoutgassing materials characteristics and properties, black orwhite light visual examination, BRDF, and so forth. Specifymethodology for obtaining representative samples and methodof analysis for witness samples such as reflectance of mirrors,image analysis
48、, direct quantitative measurement, black orwhite light visual examination, BRDF, and so forth. State thefrequency of sampling, whether sampling is directly on thehardware or via witness samples, and the justification for thesampling plan. Define the calibration of equipment used forcleanliness verif
49、ication tests.4.3.3 Materials ControlDescribe the process for controland disposition of discrepant materials. Identify the documentswhich contain approved materials and those which have beenapproved by waiver.4.3.4 Maintaining Cleanliness RequirementsThe CCPmust address the environmental controls and protection andprevention plans which will be imposed to maintain thehardware cleanliness requirements. This includes test environ-ments such as acoustic and thermal vacuum chambers, clean-rooms, shipping containers, and so forth, as well as assemblyareas and st
