1、Designation: E1235 08 E1235 12Standard Test Method forGravimetric Determination of Nonvolatile Residue (NVR) inEnvironmentally Controlled Areas for Spacecraft1This standard is issued under the fixed designation E1235; the number immediately following the designation indicates the year oforiginal ado
2、ption or, 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 nonvolatile residue (NVR)
3、fallout in environmentally controlled areas used forthe assembly, testing, and processing of spacecraft.1.2 The NVR of interest is that which is deposited on sampling plate surfaces at room temperature: it is left to the user to inferthe relationship between the NVR found on the sampling plate surfa
4、ce and that found on any other surfaces.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatoryli
5、mitations prior to use.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE1234 Practice for Handling, Transporting, and Installing Nonvolatile R
6、esidue (NVR) Sample Plates Used in EnvironmentallyControlled Areas for SpacecraftF50 Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms UsingInstruments Capable of Detecting Single Sub-Micrometre and Larger Particles2.2 ISO Standards:314644-1 C
7、leanrooms and Associated Controlled EnvironmentsPart 1: Classification of Air Cleanliness14644-2 Cleanrooms and Associated Controlled EnvironmentsPart 2: Specifications for Testing and Monitoring to ProveContinued Compliance with ISO 14644-114951-3 Space SystemsFluid CharacteristicsPart 3: Nitrogen2
8、.3 U.S. Federal Standard:4FED-STD-209E Airborne Particulate Cleanliness Classes in Cleanrooms 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
9、 Product Cleanliness Levels and Contamination Control Program2.5 American National Standards Institute:3ANSI/ASME B46.1-1985B46.1-2009 Surface Texture (Surface Roughness, Waviness, and Lay)2.6 Other:Industrial Ventilation, A Manual of Recommended Practice, Latest Edition6SMC-TR-95-28, Nonvolatile Re
10、sidue Solvent Replacement, U.S. Air Force Space and Missile Systems Center, 1 March 199543. Terminology3.1 Definitions:3.1.1 ISO Class N (airborne particulate cleanliness class), nlevel of airborne particulate concentrations as defined in ISO14644-1 and 14644-2, where 10N is the maximum allowable co
11、ncentration (particles/m3).3.1.1.1 Discussion2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3 Available fro
12、m American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from Standardization Documents Order Desk, Bldg. 4, Section D,700 Robbins Ave., Philadelphia, PA, 19111-5094, Attn.: NPODS.5 Available from Institute of Environmental Sciences
13、, 940 E. NorthwestHighway, Mount Prospect, IL 60056.6 Available from Committee on Industrial Ventilation, PO Box 16153, Lansing,MI 48901.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1The considered particle sizes (lower threshold va
14、lues) applicable for classification with ISO 14644-1 are limited to the range from0.1 through 5 m. Particles larger than 5 m (macroparticles) may be expressed in accordance with Annex E of ISO 14644-1.3.1.2 FS209 class, nthe level of cleanliness specified by the maximum allowable number of particles
15、/ft3 of air as defined inFED-STD-209E.3.1.2.1 DiscussionThis is provided for information and to facilitate the transition to the use of the ISO classification standard (ISO 14644-1).3.1.3 bumping, nuneven boiling of a liquid caused by irregular rapid escape of large bubbles of highly volatile compon
16、entsas the liquid mixture is heated or exposed to vacuum.3.1.4 clean area, na general term that includes cleanrooms, controlled areas, good housekeeping areas, and other areas thathave contamination control by physical design and specified operating procedures.3.1.5 clean zone, na defined space in w
17、hich the contamination is controlled to meet specified cleanliness levels.3.1.5.1 DiscussionThe clean zone may be open or enclosed and may or may not be located within a cleanroom.3.1.6 contaminant, nunwanted molecular and particulate matter that could affect or degrade the performance of thecompone
18、nts upon which they reside.3.1.7 contamination, na process of contaminating.3.1.8 controlled area, nan environmentally controlled area, operated as a cleanroom, with two prefilter stages but without thefinal stage of HEPA (or better) filters used in cleanrooms.3.1.8.1 DiscussionOnly rough filters (5
19、0 to 60 % efficiency) and medium efficiency filters (80 to 85 % efficiency) are required for a controlled area.The maximum allowable airborne particle concentrations are ISO Class 8.5 (FS209 Class 283 000) area for particles 0.5 m andISO Class 8 (FS209 Class 100 000) for particles 5.0 m.3.1.9 enviro
20、nmentally controlled areas, n a general term that includes cleanrooms, controlled areas, good housekeeping areas,and other enclosures that are designed to provide an environment suitable for people or products.3.1.9.1 DiscussionThe environmental components that are controlled include, but are not be
21、 limited to, air purity, temperature, humidity, materials,garments, and personnel activities.3.1.10 facility (clean facility), nthe total real property required to accomplish the cleanroom functions.3.1.10.1 DiscussionIn addition to the cleanroom and associated clean areas, this includes utility roo
22、ms, storage areas, offices, lockers, washrooms, andother areas that do not necessarily require precise environmental control.3.1.11 good housekeeping area, nan environmentally controlled area without quantitative cleanliness requirements butmaintained in a visibly clean condition.3.1.11.1 Discussion
23、Office, laboratory, and storage areas with air conditioning and janitorial service are typical of good housekeeping areas.3.1.12 HEPA (high effciency particulate air) filter, na filter for air with a removal efficiency in excess of 99.97 % for 0.3-mparticles.1 This test method is under the jurisdict
24、ion of ASTM Committee E21 on Space Simulation and Applications of Space Technology and is the responsibility of SubcommitteeE21.05 on Contamination.Current edition approved May 1, 2008Nov. 1, 2012. Published June 2008November 2012. Originally approved in 1988. Last previous edition approved in 20012
25、008 asE1235 01.E1235 08. DOI: 10.1520/E1235-08.10.1520/E1235-12.E1235 1223.1.12.1 DiscussionFor this application, HEPA filters shall meet the requirements of IEST-RP-CC001.3, IEST-RP-CC007.1, IEST-RP-CC034.1, and6.4 of this test method.3.1.13 molecular contaminant nonparticulate contaminant, nnonpar
26、ticulate matter.3.1.13.1 DiscussionThe molecular contaminant may be in a gaseous, liquid, or solid state. It may be uniformly or nonuniformly distributed or be inthe form of droplets. Molecular contaminants account for most of the NVR.3.1.14 NVR (nonvolatile residue), nquantity of residual soluble,
27、suspended, and particulate matter remaining after thecontrolled evaporation of a volatile liquid at a specified temperature.3.1.14.1 DiscussionThe liquid is usually filtered through a membrane filter, of a specified size, before evaporation to control the sizes of particles inthe NVR. The process us
28、ed to determine the NVR may affect the quantitative measurement. Process factors include filter size,solvent, and the evaporation temperature and atmosphere. For this reason, the process must be defined as it is in this test method.3.1.15 particle (particulate contaminant), n a piece of matter in a
29、solid or liquid (droplet) state with observable length, width,and thickness.3.1.16 particle size, n(1) the apparent maximum linear dimension of a particle in the plane of observation, as observed withan optical microscope; (2) the equivalent diameter of a particle detected by automatic instrumentati
30、on. The equivalent diameteris the diameter of a reference sphere having known properties and producing the same response in the sensing instrument as theparticle being measured; (3) the diameter of a circle having the same area as the projected area of a particle, in the plane ofobservation, observe
31、d by image analysis; and (4) the size defined by the measurement technique and calibration procedure.3.1.16.1 DiscussionBecause the particle size is defined by the measurement method, the measurement method and size definition should be stated whenspecifying or describing particle size.3.1.17 azeotr
32、opic mixture, na solution of two or more liquids, the composition of which does not change upon distillation.Also known as azeotrope.4. Summary of Test Method4.1 A stainless steel plate is exposed within an environmentally controlled area for a known time. It is handled and transportedin accordance
33、with Practice E1234.4.2 The plate is rinsed with a high purity solvent.4.3 The solvent is filtered into a beaker, transferred to a preweighed container, and evaporated at or near room temperature, witha final drying at 35C for 30 min. Alternative evaporation methods are included.4.4 The NVR sample i
34、s weighed after it has equilibrated to room temperature and humidity conditions.4.5 A blank stainless steel NVR plate is concurrently treated identically to each group of samples to determine solventbackground and handling effects.4.6 A reagent blank for each group of samples is determined.4.7 Each
35、NVR sample, 0.5 mg or greater, is retained for organic analysis by infrared spectrometry, or other techniques, toidentify contaminants.5. Significance and Use5.1 The NVR determined by this test method is that amount that can reasonably be expected to exist on hardware exposed inenvironmentally contr
36、olled areas.5.2 The evaporation of the solvent at or near room temperature is to quantify the NVR that exists at room temperature.5.3 Numerous other methods are being used to determine NVR. This test method is not intended to replace methods used forother applications.E1235 1236. Apparatus and Mater
37、ials6.1 Analytical Microbalance, semimicro 5 place, with 30 g or greater tare, no greater than 0.01-mg readability, and 60.01-mgprecision.76.2 HEPA Filtered, ISO Class 5 (FS209 Class 100), or better environment, as defined in ISO 14644-1, unidirectional airflow,clean workstation.6.3 HEPA Filtered, I
38、SO Class 5 (FS209 Class 100), or better environment, as defined in ISO 14644-1, unidirectional air flow,exhausting work station, with 100 % exhaust for handling solvents.NOTE 1The exhausting work station is recommended to prevent solvent vapors from entering the laboratory area (see Industrial Venti
39、lation, a Manualof Recommended Practice).NOTE 2Verify that the airborne particle concentrations in the work stations are ISO Class 5 FS209 Class 100, or better, per ISO 14644-1, when testedin accordance with Practice F50.NOTE 3Verify NVR levels in the work stations are acceptable using the procedure
40、s in this standard.6.4 HEPA FiltersAll HEPA filters shall be constructed of low outgassing, corrosion-resistant, and fire-resistant materials suchas Grade 1 in IEST-RP-CC001.3. Filters with stainless steel or aluminum frames should be considered. The filters shall not betested with DOP (dioctylphtha
41、late) or other liquid aerosols. Ambient air and solid aerosol test methods are acceptable alternativesto the DOP test. Applicable test methods from IEST-RP-CC007.1 and IEST-RP-CC034.1 shall be considered.6.5 Vacuum Filtration System, consisting of a 47-mm-diameter membrane filter funnel8 and vacuum
42、pump that will provide apressure of 30 kPa (250 torr) (a vacuum of 20 in. Hg). See Fig. 1.6.6 Solvent-Resistant Filter, 47-mm diameter,9 0.2-m pore size (nominal) fluorocarbon.6.7 Tweezers or Hemostat, stainless steel or coated with TFE-fluorocarbon.6.8 Beakers, low-form, glass, 250 mL, etched with
43、an identification number.6.9 Evaporating Dish (Petri Dish), borosilicate glass, approximately 15 g in mass, 60-mm diameter by 12 mm deep, and etchedwith an identification number.6.10 Liquid Laboratory Detergent.6.11 Gloves, solvent compatible and resistant.10 (WarningGloves shall be used to protect
44、the hands from accidental spills ofthe NVR solvent and minimize contamination of exposed samples. Gloves shall be selected to meet local safety and contaminationcontrol requirements.)6.12 NVR Plate, Type 316 corrosion-resistant steel with an area of approximately 0.1 m2 (1 ft2). The plate shown in F
45、ig. 2 hasbeen found to be satisfactory. The finish of the sampling surface shall be 0.80 m (32 in.) or better per ANSI/ASME B46.1. Theplate shall be electropolished and engraved with an identification number.7 Sartorius Model R180D, or equivalent.8 Gelman filter funnel P/N 4012/Fisher filtrator asse
46、mbly Cat. No. 09-788 and Millipore Cat. No. XX1504700 filtration assembly have been found to be satisfactory. Othersuitable filtration apparatus may be used.9 Millipore Corp. Fluoropore filter Cat. No. FGLP 04700, and Gelman Sciences, Inc. Prod. 66143 PTFE have been found to be satisfactory. Other e
47、quivalent solventresistant filters may be used.10 Pioneer green nitrile gloves, Catalog No. A10-1, have been found to be satisfactory.FIG. 1 Vacuum Filtration ApparatusE1235 1246.13 NVR Plate Cover, Type 316 corrosion-resistant steel. The cover shown in Fig. 3 has been found to be satisfactory. Thef
48、inish shall be 0.80 m (32 in.) or better per ANSI/ASME B46.1. The cover shall be electropolished and engraved with anidentification number.6.14 Oil-Free Aluminum Foil11, to cover the NVR plate if the cover (6.12) is not used.11 Fed Spec. Food Service Grade aluminum foil, oil free, Federal Stock No.
49、8135-00-724-0551 has been found to be satisfactory.FIG. 2 NVR Collector PlateFIG. 3 NVR Plate CoverE1235 125NOTE 4The hard cover (6.13) is preferred for ease of handling and possible tearing of the foil resulting in contamination of the NVR plate.6.15 Noncontaminating Nylon Bag to enclose each covered NVR plate.126.15.1 Bags shall not contain or generate molecular or particulate matter that could contaminate the NVR plate or NVR platecarrier.6.16 NVR Plate CarrierThe sealable, aluminum carrier shown in Fig. 4 has been fo
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