1、Designation: E 1235 08Standard Test Method forGravimetric Determination of Nonvolatile Residue (NVR) inEnvironmentally Controlled Areas for Spacecraft1This standard is issued under the fixed designation E 1235; the number immediately following the designation indicates the year oforiginal adoption o
2、r, in the 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.1. Scope1.1 This test method covers the determination of nonvolatileresidue (NVR) fallout
3、in environmentally controlled areas usedfor the assembly, testing, and processing of spacecraft.1.2 The NVR of interest is that which is deposited onsampling plate surfaces at room temperature: it is left to theuser to infer the relationship between the NVR found on thesampling plate surface and tha
4、t found on any other surfaces.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitation
5、s prior to use.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 1234 Practice for Handling, Transporting, and InstallingNonvolatile Residue (N
6、VR) Sample Plates Used in Envi-ronmentally Controlled Areas for SpacecraftF50 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 Particles2.2 ISO Standards:314644-1 Cleanro
7、oms and Associated ControlledEnvironmentsPart 1: Classification of Air Cleanliness14644-2 Cleanrooms and Associated ControlledEnvironmentsPart 2: Specifications for Testing andMonitoring to Prove Continued Compliance with ISO14644-114951-3 Space SystemsFluid CharacteristicsPart 3: Ni-trogen2.3 U.S.
8、Federal Standard:4FED-STD-209E Airborne Particulate Cleanliness Classes inCleanrooms and Clean Zones2.4 Institute of Environmental Sciences and Technology:5IEST-RP-CC001.3 HEPA and ULPA FiltersIEST-RP-CC007.1 Testing ULPA FiltersIEST-RP-CC034.1 HEPA and ULPA Filter Leak TestsIEST-STD-CC1246 Product
9、Cleanliness Levels and Con-tamination Control Program2.5 American National Standards Institute:3ANSI/ASME B46.1-1985 Surface Texture (Surface Rough-ness, Waviness, and Lay)2.6 Other:Industrial Ventilation, A Manual of Recommended Practice,Latest Edition6SMC-TR-95-28, Nonvolatile Residue Solvent Repl
10、acement,U.S. Air Force Space and Missile Systems Center, 1March 199543. Terminology3.1 Definitions:3.1.1 ISO Class N (airborne particulate cleanliness class),nlevel of airborne particulate concentrations as defined inISO 14644-1 and 14644-2, where 10Nis the maximumallowable concentration (particles/
11、m3).3.1.1.1 DiscussionThe considered particle sizes (lowerthreshold values) applicable for classification with ISO14644-1 are limited to the range from 0.1 through 5 m.Particles larger than 5 m (macroparticles) may be expressed inaccordance with Annex E of ISO 14644-1.3.1.2 FS209 class, nthe level o
12、f cleanliness specified bythe maximum allowable number of particles/ft3of air asdefined in FED-STD-209E.1This test method is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the responsibility ofSubcommittee E21.05 on Contamination.Current e
13、dition approved May 1, 2008. Published June 2008. Originallyapproved in 1988. Last previous edition approved in 2001 as E 1235 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informat
14、ion, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from Standardization Documents Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia,
15、 PA, 19111-5094, Attn.: NPODS.5Available from Institute of Environmental Sciences, 940 E. Northwest High-way, Mount Prospect, IL 60056.6Available from Committee on Industrial Ventilation, PO Box 16153, Lansing,MI 48901.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
16、ken, PA 19428-2959, United States.3.1.2.1 DiscussionThis is provided for information and tofacilitate the transition to the use of the ISO classificationstandard (ISO 14644-1).3.1.3 bumping, nuneven boiling of a liquid caused byirregular rapid escape of large bubbles of highly volatilecomponents as
17、the liquid mixture is heated or exposed tovacuum.3.1.4 clean area, na general term that includes clean-rooms, controlled areas, good housekeeping areas, and otherareas that have contamination control by physical design andspecified operating procedures.3.1.5 clean zone, na defined space in which the
18、 contami-nation is controlled to meet specified cleanliness levels.3.1.5.1 DiscussionThe clean zone may be open or en-closed and may or may not be located within a cleanroom.3.1.6 contaminant, nunwanted molecular and particulatematter that could affect or degrade the performance of thecomponents upo
19、n which they reside.3.1.7 contamination, na process of contaminating.3.1.8 controlled area, nan environmentally controlledarea, operated as a cleanroom, with two prefilter stages butwithout the final stage of HEPA (or better) filters used incleanrooms.3.1.8.1 DiscussionOnly rough filters (50 to 60 %
20、 effi-ciency) and medium efficiency filters (80 to 85 % efficiency)are required for a controlled area. The maximum allowableairborne particle concentrations are ISO Class 8.5 (FS209Class 283 000) area for particles 0.5 m and ISO Class 8(FS209 Class 100 000) for particles 5.0 m.3.1.9 environmentally
21、controlled areas, na general termthat includes cleanrooms, controlled areas, good housekeepingareas, and other enclosures that are designed to provide anenvironment suitable for people or products.3.1.9.1 DiscussionThe environmental components thatare controlled include, but are not be limited to, a
22、ir purity,temperature, humidity, materials, garments, and personnelactivities.3.1.10 facility (clean facility), nthe total real propertyrequired to accomplish the cleanroom functions.3.1.10.1 DiscussionIn addition to the cleanroom and as-sociated clean areas, this includes utility rooms, storage are
23、as,offices, lockers, washrooms, and other areas that do notnecessarily require precise environmental control.3.1.11 good housekeeping area, nan environmentallycontrolled area without quantitative cleanliness requirementsbut maintained in a visibly clean condition.3.1.11.1 DiscussionOffice, laborator
24、y, and storage areaswith air conditioning and janitorial service are typical of goodhousekeeping areas.3.1.12 HEPA (high effciency particulate air) filter, nafilter for air with a removal efficiency in excess of 99.97 % for0.3-m particles.3.1.12.1 DiscussionFor this application, HEPA filtersshall me
25、et the requirements of IEST-RP-CC001.3, IEST-RP-CC007.1, IEST-RP-CC034.1, and 6.4 of this test method.3.1.13 molecular contaminantnonparticulate contami-nant, nnonparticulate matter.3.1.13.1 DiscussionThe molecular contaminant may be ina gaseous, liquid, or solid state. It may be uniformly ornonunif
26、ormly distributed or be in the form of droplets. Mo-lecular contaminants account for most of the NVR.3.1.14 NVR (nonvolatile residue), nquantity of residualsoluble, suspended, and particulate matter remaining after thecontrolled evaporation of a volatile liquid at a specifiedtemperature.3.1.14.1 Dis
27、cussionThe liquid is usually filtered througha membrane filter, of a specified size, before evaporation tocontrol the sizes of particles in the NVR. The process used todetermine the NVR may affect the quantitative measurement.Process factors include filter size, solvent, and the evaporationtemperatu
28、re and atmosphere. For this reason, the process mustbe defined as it is in this test method.3.1.15 particle (particulate contaminant), na piece ofmatter in a solid or liquid (droplet) state with observablelength, width, and thickness.3.1.16 particle size, n(1) the apparent maximum lineardimension of
29、 a particle in the plane of observation, as observedwith an optical microscope; (2) the equivalent diameter of aparticle detected by automatic instrumentation. The equivalentdiameter is the diameter of a reference sphere having knownproperties and producing the same response in the sensinginstrument
30、 as the particle being measured; (3) the diameter ofa circle having the same area as the projected area of a particle,in the plane of observation, observed by image analysis; and(4) the size defined by the measurement technique and calibra-tion procedure.3.1.16.1 DiscussionBecause the particle size
31、is defined bythe measurement method, the measurement method and sizedefinition should be stated when specifying or describingparticle size.3.1.17 azeotropic mixture, na solution of two or moreliquids, the composition of which does not change upondistillation. Also known as azeotrope.4. Summary of Te
32、st Method4.1 A stainless steel plate is exposed within an environmen-tally controlled area for a known time. It is handled andtransported in accordance with Practice E 1234.4.2 The plate is rinsed with a high purity solvent.4.3 The solvent is filtered into a beaker, transferred to apreweighed contai
33、ner, and evaporated at or near room tempera-ture, with a final drying at 35C for 30 min. Alternativeevaporation methods are included.4.4 The NVR sample is weighed after it has equilibrated toroom temperature and humidity conditions.4.5 Ablank stainless steel NVR plate is concurrently treatedidentica
34、lly to each group of samples to determine solventbackground and handling effects.4.6 A reagent blank for each group of samples is deter-mined.4.7 Each NVR sample, 0.5 mg or greater, is retained fororganic analysis by infrared spectrometry, or other techniques,to identify contaminants.E12350825. Sign
35、ificance and Use5.1 The NVR determined by this test method is that amountthat can reasonably be expected to exist on hardware exposedin environmentally controlled areas.5.2 The evaporation of the solvent at or near room tempera-ture is to quantify the NVR that exists at room temperature.5.3 Numerous
36、 other methods are being used to determineNVR. This test method is not intended to replace methods usedfor other applications.6. Apparatus and Materials6.1 Analytical Microbalance, semimicro 5 place, with 30 gor greater tare, no greater than 0.01-mg readability, and60.01-mg precision.76.2 HEPA Filte
37、red, ISO Class 5 (FS209 Class 100), or betterenvironment, as defined in ISO 14644-1, unidirectional airflow,clean workstation.6.3 HEPA Filtered, ISO Class 5 (FS209 Class 100), or betterenvironment, as defined in ISO 14644-1, unidirectional airflow, exhausting work station, with 100 % exhaust for han
38、dlingsolvents.NOTE 1The exhausting work station is recommended to preventsolvent vapors from entering the laboratory area (see Industrial Ventila-tion, a Manual of Recommended Practice).NOTE 2Verify that the airborne particle concentrations in the workstations are ISO Class 5 FS209 Class 100, or bet
39、ter, per ISO 14644-1,when tested in accordance with Practice F50.NOTE 3Verify NVR levels in the work stations are acceptable usingthe procedures in this standard.6.4 HEPA FiltersAll HEPA filters shall be constructed oflow outgassing, corrosion-resistant, and fire-resistant materialssuch as Grade 1 i
40、n IEST-RP-CC001.3. Filters with stainlesssteel or aluminum frames should be considered. The filtersshall not be tested with DOP (dioctylphthalate) or other liquidaerosols. Ambient air and solid aerosol test methods areacceptable alternatives to the DOP test. Applicable test meth-ods from IEST-RP-CC0
41、07.1 and IEST-RP-CC034.1 shall beconsidered.6.5 Vacuum Filtration System, consisting of a 47-mm-diameter membrane filter funnel8and vacuum pump that willprovide a pressure of 30 kPa (250 torr) (a vacuum of 20 in.Hg). See Fig. 1.6.6 Solvent-Resistant Filter, 47-mm diameter,90.2-m poresize (nominal) f
42、luorocarbon.6.7 Tweezers or Hemostat, stainless steel or coated withTFE-fluorocarbon.6.8 Beakers, low-form, glass, 250 mL, etched with anidentification number.6.9 Evaporating Dish (Petri Dish), borosilicate glass, ap-proximately 15 g in mass, 60-mm diameter by 12 mm deep,and etched with an identific
43、ation number.6.10 Liquid Laboratory Detergent.6.11 Gloves, solvent compatible and resistant.10(WarningGloves shall be used to protect the hands fromaccidental spills of the NVR solvent and minimize contamina-tion of exposed samples. Gloves shall be selected to meet localsafety and contamination cont
44、rol requirements.)6.12 NVR Plate, Type 316 corrosion-resistant steel with anarea of approximately 0.1 m2(1 ft2). The plate shown in Fig. 2has been found to be satisfactory. The finish of the samplingsurface shall be 0.80 m (32 in.) or better per ANSI/ASMEB46.1. The plate shall be electropolished and
45、 engraved with anidentification number.6.13 NVR Plate Cover, Type 316 corrosion-resistant steel.The cover shown in Fig. 3 has been found to be satisfactory.The finish shall be 0.80 m (32 in.) or better perANSI/ASMEB46.1. The cover shall be electropolished and engraved with anidentification number.6.
46、14 Oil-Free Aluminum Foil11, to cover the NVR plate ifthe cover (6.12) is not used.NOTE 4The hard cover (6.13) is preferred for ease of handling andpossible tearing of the foil resulting in contamination of the NVR plate.6.15 Noncontaminating Nylon Bag to enclose each coveredNVR plate.126.15.1 Bags
47、shall not contain or generate molecular orparticulate matter that could contaminate the NVR plate orNVR plate carrier.6.16 NVR Plate CarrierThe sealable, aluminum carriershown in Fig. 4 has been found to be satisfactory (see PracticeE 1234).6.17 Drying Oven:6.17.1 The drying oven shall not produce m
48、olecular andparticulate contaminants and shall not be used for otheroperations that could contaminate samples.6.18 Plate StandThe plate stand shown in Fig. 5 has beenfound useful for holding the NVR plate during solvent flush-ing.7Sartorius Model R180D, or equivalent.8Gelman filter funnel P/N 4012/F
49、isher filtrator assembly Cat. No. 09-788 andMillipore Cat. No. XX1504700 filtration assembly have been found to be satisfac-tory. Other suitable filtration apparatus may be used.9Millipore Corp. Fluoropore filter Cat. No. FGLP 04700, and Gelman Sciences,Inc. Prod. 66143 PTFE have been found to be satisfactory. Other equivalent solventresistant filters may be used.10Pioneer green nitrile gloves, Catalog No. A10-1, have been found to besatisfactory.11Fed Spec. Food Service Grade aluminum foil, oil free, Federal Stock No.8135-00-724-
