1、Designation: E 1235 01Standard 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 (e) 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 th
4、at 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 limitatio
5、ns prior to use.1.4 The values stated in SI units are to be regarded as thestandard.2. Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water2E 1234 Practice for Handling, Transporting, and InstallingNonvolatile Residue (NVR) Sample Plates Used in Envi-ronmentally Controlled A
6、reas for Spacecraft3F 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 Particles32.2 ISO Standards:14644-1 Cleanrooms and Associated ControlledEnvironmentsPart 1: Clas
7、sification of Air Cleanliness414644-2 Cleanrooms and Associated ControlledEnvironmentsPart 2: Specifications for Testing andMonitoring to Prove Continued Compliance with ISO14644-1414951-3 Space SystemsFluid CharacteristicsPart 3: Ni-trogen42.3 U.S. Federal Standard:FED-STD-209E Airborne Particulate
8、 Cleanliness Classes inCleanrooms and Clean Zones52.4 Institute of Environmental Sciences and Technology:IEST-RP-CC001.3 HEPA and ULPA Filters6IEST-RP-CC007.1 Testing ULPA Filters6IEST-RP-CC034.1 HEPA and ULPA Filter Leak Tests6IEST-STD-CC1246 Product Cleanliness Levels and Con-tamination Control Pr
9、ogram62.5 American National Standards Institute:ANSI/ASME B46.1-1985 Surface Texture (Surface Rough-ness, Waviness, and Lay)42.6 Other:Industrial Ventilation, A Manual of Recommended Practice,Latest Edition7SMC-TR-95-28, Nonvolatile Residue Solvent Replacement,U.S. Air Force Space and Missile System
10、s Center, 1March 199553. 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/m3).3.1.1.1 DiscussionThe considered particle s
11、izes (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 of cleanliness specified bythe maximum allowable
12、 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 edition approved Oct. 10, 2001. Published Januar
13、y 2002. Originallypublished as E 1235 88. Last previous edition E 1235 95e1.2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 15.03.4Available from the American National Standards Institute, 25 W. 43rd St., 4thFloor, New York NY 10036.5Available from Standardization Docum
14、ents Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA, 19111-5094, Attn.: NPODS.6Available from Institute of Environmental Sciences, 940 E. Northwest High-way, Mount Prospect, IL 60056.7Available from Committee on Industrial Ventilation, PO Box 16153, Lansing,MI 48901.1Copyright AST
15、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, 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 byirreg
16、ular rapid escape of large bubbles of highly volatilecomponents as 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 o
17、perating procedures.3.1.5 clean zone, na defined space in which the 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 particulatematte
18、r that could affect or degrade the performance of thecomponents upon 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
19、 used incleanrooms.3.1.8.1 DiscussionOnly rough filters (50 to 60 % 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 Clas
20、s 8(FS209 Class 100 000) for particles 5.0 m.3.1.9 environmentally 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
21、components thatare controlled include, but are not be limited to, air 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 an
22、d as-sociated clean areas, this includes utility rooms, storage areas,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 maintaine
23、d in a visibly clean condition.3.1.11.1 DiscussionOffice, laboratory, 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 part
24、icles.3.1.12.1 DiscussionFor this application, HEPA filtersshall meet 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
25、 ina gaseous, liquid, or solid state. It may be uniformly ornonuniformly 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 evap
26、oration of a volatile liquid at a specifiedtemperature.3.1.14.1 DiscussionThe 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
27、 factors include filter size, solvent, and the evaporationtemperature 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
28、.3.1.16 particle size, n(1) the apparent maximum lineardimension of 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 known
29、properties and producing the same response in the sensinginstrument 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 c
30、alibra-tion procedure.3.1.16.1 DiscussionBecause the particle size 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 no
31、t change upondistillation. Also known as azeotrope.4. Summary of Test 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 methylene chlorid
32、esolvent.4.3 The solvent is filtered into a beaker, transferred to apreweighed container, 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 hum
33、idity conditions.4.5 A blank stainless steel NVR plate is concurrently treatedidentically 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
34、by infrared spectrometry, or other techniques,to identify contaminants.E12350125. Significance 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
35、 room tempera-ture is to quantify the NVR that exists at room temperature.5.3 Numerous 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 gr
36、eater tare, no greater than 0.01-mg readability, and60.01-mg precision.86.2 HEPA Filtered, 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 IS
37、O 14644-1, unidirectional airflow, exhausting work station, with 100 % exhaust for handlingsolvents.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 airbor
38、ne particle concentrations in the workstations are ISO Class 5 FS209 Class 100, or better, per ISO 14644-1,when tested in accordance with Practice F 50.NOTE 3Verify NVR levels in the work stations are acceptable usingthe procedures in this standard.6.4 HEPA FiltersAll HEPA filters shall be construct
39、ed oflow outgassing, corrosion-resistant, and fire-resistant materialssuch as Grade 1 in 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 method
40、s areacceptable alternatives to the DOP test. Applicable test meth-ods from IEST-RP-CC007.1 and IEST-RP-CC034.1 shall beconsidered.6.5 Vacuum Filtration System, consisting of a 47-mm-diameter membrane filter funnel9and vacuum pump that willprovide a pressure of 30 kPa (250 torr) (a vacuum of 20 in.H
41、g). See Fig. 1.6.6 Solvent-Resistant Filter, 47-mm diameter,100.2-mpore size (nominal) fluorocarbon.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
42、, ap-proximately 15 g in mass, 60-mm diameter by 12 mm deep,and etched with an identification number.6.10 Liquid Laboratory Detergent.6.11 Gloves, solvent compatible and resistant.11(WarningGloves shall be used to protect the hands fromaccidental spills of the NVR solvent and minimize contamina-tion
43、 of exposed samples. Gloves shall be selected to meet localsafety and contamination control 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
44、 be 0.80 m (32 in.) or better per ANSI/ASMEB46.1. The plate shall be electropolished and 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 per ANSI/A
45、SMEB46.1. The cover shall be electropolished and engraved with anidentification number.6.14 Oil-Free Aluminum Foil12, 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
46、NVR plate.6.15 Noncontaminating Nylon Bag to enclose each coveredNVR plate.136.15.1 Bags 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 sati
47、sfactory (see PracticeE 1234).6.17 Noncontaminating Nylon Bag13to protect the NVRplate carrier in 6.15. Plastic film material shall meet the safetyand outgassing requirements for the spacecraft and spacecraftprocessing facility (see Note 4).6.18 Drying Oven:8Sartorius Model R180D, or equivalent.9Gel
48、man filter funnel P/N 4012/Fisher 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.10Millipore Corp. Fluoropore filter Cat. No. FGLP 04700, and Gelman Sciences,Inc. Prod. 66143
49、PTFE have been found to be satisfactory. Other equivalent solventresistant filters may be used.11Pioneer green nitrile gloves, Catalog No. A10-1, have been found to besatisfactory.12Fed Spec. Food Service Grade aluminum foil, oil free, Federal Stock No.8135-00-724-0551 has been found to be satisfactory.13Nylon 6 (heat-sealable Capran 980 from Allied Chemical) has been found tobe satisfactory.FIG. 1 Vacuum Filtration ApparatusE12350136.18.1 The drying oven shall not produce molecular andparticulate contaminants and shall not be used
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