ASTM E1235-95e1

Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft

SCOPE
1.1 This test method covers the determination of nonvolatile residue (NVR) fallout in environmentally controlled areas used for the 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 infer the relationship between the NVR found on the sampling plate surface 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 responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.4 The values stated in SI units are to be regarded as the standard.

General Information

• Status: Historical
• Publication Date: 09-Oct-2001
• ICS: 49.025.01 - Materials for aerospace construction in general
• ICS: 49.140 - Space systems and operations
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.05 - Contamination

Relations

• Replaced By: ASTM E1235-01 - Standard Test Method for Gravimetric Determination of Nonvolatile Residue (NVR) in Environmentally Controlled Areas for Spacecraft
• Effective Date: 10-Oct-2001
• Referred By: ASTM E1548-09(2022) - Standard Practice for Preparation of Aerospace Contamination Control Plans
• Effective Date: 10-Oct-2001
• Referred By: ASTM G131-96(2023)e1 - Standard Practice for Cleaning of Materials and Components by Ultrasonic Techniques
• Effective Date: 10-Oct-2001
• Referred By: ASTM E2900-19 - Standard Practice for Spacecraft Hardware Thermal Vacuum Bakeout
• Effective Date: 10-Oct-2001
• Referred By: ASTM E2352-19 - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments—Cleanroom Operations
• Effective Date: 10-Oct-2001
• Referred By: ASTM G120-15(2023) - Standard Practice for Determination of Soluble Residual Contamination by Soxhlet Extraction
• Effective Date: 10-Oct-2001
• Referred By: ASTM E2042/E2042M-09(2021) - Standard Practice for Cleaning and Maintaining Controlled Areas and Clean Rooms
• Effective Date: 10-Oct-2001
• Referred By: ASTM E2312-11(2019) - Standard Practice for Tests of Cleanroom Materials
• Effective Date: 10-Oct-2001
• Referred By: ASTM G121-18 - Standard Practice for Preparation of Contaminated Test Coupons for the Evaluation of Cleaning Agents
• Effective Date: 10-Oct-2001
• Referred By: ASTM G136-03(2023)e1 - Standard Practice for Determination of Soluble Residual Contaminants in Materials by Ultrasonic Extraction
• Effective Date: 10-Oct-2001
• Referred By: ASTM E1234-12(2020) - Standard Practice for Handling, Transporting, and Installing Nonvolatile Residue (NVR) Sample Plates Used in Environmentally Controlled Areas for Spacecraft
• Effective Date: 10-Oct-2001
• Referred By: ASTM E2217-12(2019) - Standard Practice for Design and Construction of Aerospace Cleanrooms and Contamination Controlled Areas
• Effective Date: 10-Oct-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: E 1235 – 95
Standard Test Method for
Gravimetric Determination of Nonvolatile Residue (NVR) in
Environmentally Controlled Areas for Spacecraft [Metric]
This standard is issued under the fixed designation E 1235; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—To bring Subcommittee E21.05’s existing standards into compliance with Part H of ASTM’s Form and Style Manual,
the M designation has been editorially removed in July 2000.
1. Scope MIL-STD-1246 Product Cleanliness Levels and Contami-
nation Control Program
1.1 This test method covers the determination of nonvolatile
T.O. 00-25-203, 1 Dec. 1972, Change 15, 24 Oct. 1992,
residue (NVR) fallout in environmentally controlled areas used
Contamination Control of Aerospace Facilities, U.S. Air
for the assembly, testing, and processing of spacecraft.
Force
1.2 The NVR of interest is that which is deposited on
2.4 Institute of Environmental Sciences:
sampling plate surfaces at room temperature: it is left to the
IES-RP-CC001.3 HEPA and ULPA Filters
user to infer the relationship between the NVR found on the
IES-RP-CC006.2 Testing Cleanrooms
sampling plate surface and that found on any other surfaces.
IES-RP-CC016.1 The Rate of Deposition of Nonvolatile
1.3 This standard does not purport to address all of the
Residue in Cleanrooms
safety concerns, if any, associated with its use. It is the
2.5 American National Standards Institute:
responsibility of the user of this standard to establish appro-
ANSI/ASME B46.1-1985 Surface Texture (Surface Rough-
priate safety and health practices and determine the applica-
ness, Waviness, and Lay)
bility of regulatory limitations prior to use.
2.6 Other:
1.4 The values stated in SI units are to be regarded as the
Industrial Ventilation, A Manual of Recommended Practice,
standard.
Latest Edition
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
3.1 Definitions:
D 1193 Specification for Reagent Water
3.1.1 air cleanliness class (airborne particulate cleanliness
E 1234 Practice for Handling, Transporting, and Installing
class), n—the level of cleanliness specified by the maximum
Nonvolatile Residue (NVR) Sample Plates Used in Envi-
allowable number of particles per cubic meter (cubic foot) of
ronmentally Controlled Areas for Spacecraft
air as defined in FED-STD-209.
F 50 Practice for Continuous Sizing and Counting of Air-
3.1.2 bumping, n—uneven boiling of a liquid caused by
borne Particles in Dust-Controlled Areas and Clean Rooms
irregular rapid escape of large bubbles of highly volatile
Using Instruments Capable of Detecting Single Sub-
3 components as the liquid mixture is heated or exposed to
Micrometre and Larger Particles
vacuum.
2.2 U.S. Federal Standard:
3.1.3 clean area, n—a general term that includes clean-
FED-STD-209 Airborne Particulate Cleanliness Classes in
rooms, controlled areas, good housekeeping areas, and other
Cleanrooms and Clean Zones
4 areas that have contamination control by physical design and
2.3 U.S. Department of Defense Standards:
specified operating procedures.
MIL-F-51068F Filters, Particulate (High-Efficiency Fire
3.1.4 clean zone, n—a defined space in which the contami-
Resistant)
nation is controlled to meet specified cleanliness levels.
MIL-P-27401 Propellant Pressurizing Agent, Nitrogen
3.1.4.1 Discussion—The clean zone may be open or en-
closed and may or may not be located within a cleanroom.
This test method is under the jurisdiction of ASTM Committee E-21 on Space
Simulation and Applications of Space Technology and is the responsibility of
Subcommittee E21.05 on Contamination.
Current edition approved Aug. 15, 1995. Published October 1995. Originally Available from Institute of Environmental Sciences, 940 E. Northwest High-
published as E 1235 – 88. Last previous edition E 1235 – 88 (1993). way, Mount Prospect, IL 60056.
2 6
Annual Book of ASTM Standards, Vol 11.01. Available from American Society of Mechanical Engineers, United Engineer-
Annual Book of ASTM Standards, Vol 15.03. ing Center, 345 E. 47th St., New York, NY 10017.
4 7
Available from Standardization Documents Order Desk, Bldg. 4, Section D, Available from Committee on Industrial Ventilation, PO Box 16153, Lansing,
700 Robbins Ave., Philadelphia, PA, 19111-5094, Attn.: NPODS. MI 48901, American Conference of Government and Industrial Hygienists.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 1235
3.1.5 contaminant, n—unwanted molecular and particulate matter in a solid or liquid (droplet) state with observable
matter that could affect or degrade the performance of the length, width, and thickness. The size of a particle is usually
components upon which they reside. defined by its greatest dimension and is specified in microme-
3.1.6 contamination, n—a process of contaminating. tres.
3.1.14.1 Discussion—Particle sizes are also defined by
3.1.7 controlled area, n—an environmentally controlled
other parameters such as equivalent optical light scatter cros-
area, operated as a cleanroom, with two prefilter stages but
sections, diameter of spheres with equivalent projected areas.
without the final stage of HEPA (or better) filters used in
cleanrooms.
4. Summary of Test Method
3.1.7.1 Discussion—Only rough filters (50 to 60 % effi-
4.1 A stainless steel plate is exposed within an environmen-
ciency) and medium efficiency filters (80 to 85 % efficiency)
tally controlled area for a known time. It is handled and
are required for a controlled area. (See Air Force T.O. 00-25-
transported in accordance with Practice E 1234.
203). The maximum allowable airborne particle concentrations
4.2 The plate is rinsed with a high purity methylene chloride
are Class M7 (283 000) area for particles $0.5 μm and Class
solvent.
M6.5 (100 000) for particles $5.0 μm.
4.3 The solvent is filtered into a beaker, transferred to a
3.1.8 environmentally controlled areas, n—a general term
preweighed container, and evaporated at or near room tempera-
that includes cleanrooms, controlled areas, good housekeeping
ture, with a final drying at 35°C for 30 min. Alternative
areas, and other enclosures that are designed to provide an
evaporation methods are included.
environment suitable for people or products.
4.4 The NVR sample is weighed after it has equilibrated to
3.1.8.1 Discussion—The environmental components that
room temperature and humidity conditions.
are controlled include, but are not be limited to, air purity,
4.5 A blank stainless steel NVR plate is concurrently treated
temperature, humidity, materials, garments, and personnel
identically to each group of samples to determine solvent
activities.
background and handling effects.
3.1.9 facility (clean facility), n—the total real property
4.6 A reagent blank for each group of samples is deter-
required to accomplish the cleanroom functions.
mined.
3.1.9.1 Discussion—In addition to the cleanroom and asso-
4.7 Each NVR sample, 0.5 mg or greater, is retained for
ciated clean areas, this includes utility rooms, storage areas,
organic analysis by infrared spectrometry, or other techniques,
offices, lockers, washrooms, and other areas that do not
to identify contaminants.
necessarily require precise environmental control.
3.1.10 good housekeeping area, n—an environmentally
5. Significance and Use
controlled area without quantitative cleanliness requirements
5.1 The NVR determined by this test method is that amount
but maintained in a visibly clean condition.
that can reasonably be expected to exist on hardware exposed
3.1.10.1 Discussion—Office, laboratory, and storage areas
in environmentally controlled areas.
with air conditioning and janitorial service are typical of good
5.2 The evaporation of the solvent at or near room tempera-
housekeeping areas.
ture is to quantify the NVR that exists at room temperature.
3.1.11 HEPA (high effıciency particulate air) filter, n—a
5.3 Numerous other methods are being used to determine
filter for air with a removal efficiency in excess of 99.97 % for
NVR. This test method is not intended to replace methods used
0.3-μm particles.
for other applications.
3.1.11.1 Discussion—For this application, HEPA filters
shall meet the requirements of MIL-F-51068F and paragraph
6. Apparatus and Materials
6.4 of this test method.
6.1 Analytical Microbalance, semimicro 5 place, with 30 g
3.1.12 molecular contaminant—nonparticulate contami-
or greater tare, no greater than 0.01-mg readability, and
nant, n—nonparticulate matter.
60.01-mg precision.
3.1.12.1 Discussion—The molecular contaminant may be in
6.2 HEPA Filtered, Class M3.5 (Class 100), or better
a gaseous, liquid, or solid state. It may be uniformly or
environment, as defined in FED-STD-209, unidirectional air
nonuniformly distributed or be in the form of droplets. Mo-
flow, clean work station.
lecular contaminants account for most of the NVR.
6.3 HEPA Filtered, Class M3.5 (Class 100), or better
3.1.13 NVR (nonvolatile residue), n—quantity of residual
environment, as defined in FED-STD-209, unidirectional air
soluble, suspended, and particulate matter remaining after the
flow, exhausting work station, with 100 % exhaust for handling
controlled evaporation of a volatile liquid at a specified
solvents.
temperature.
NOTE 1—The exhausting work station is recommended to prevent
3.1.13.1 Discussion—The liquid is usually filtered through
solvent vapors from entering the laboratory area. (See Industrial Ventila-
a membrane filter, of a specified size, before evaporation to
tion, a Manual of Recommended Practice.)
control the sizes of particles in the NVR. The process used to
NOTE 2—Verify that the airborne particle concentrations in the work
determine the NVR may affect the quantitative measurement.
stations are Class M3.5 (Class 100), or better, per FED-STD-209, when
Process factors include filter size, solvent, and the evaporation
tested in accordance with Practice F 50.
temperature and atmosphere. For this reason, the process must
be defined as it is in this test method.
3.1.14 particle (particulate contaminant), n—a piece of Sartorius Model R180D, or equivalent.
E 1235
NOTE 3—Verify NVR levels in the work stations are acceptable using
6.13 NVR Plate Cover, Type 316 corrosion resistant steel.
the procedures in this standard.
The cover shown in Fig. 3 has been found to be satisfactory.
The finish shall be 0.80 μm (32 μin.) or better per ANSI/ASME
6.4 HEPA Filters—All HEPA filters shall be constructed of
B46.1. The cover shall be electropolished and engraved with an
low outgassing, corrosion resistant, and fire-resistant materials
identification number.
such as Grade 1 in IES-RP-CC001.3 and MIL-F-51068F. Types
6.14 Oil-Free Aluminum Foil , to cover the NVR plate if
IIA and IID, MIL-F-51068F, with stainless steel or aluminum
the cover (6.12) is not used.
frames, should be considered. The filters shall not be tested
with DOP (dioctylphthalate) or other liquid aerosols. Ambient
NOTE 4—The hard cover (6.13) is preferred for ease of handling and
air and solid aerosol test methods are acceptable alternatives to
possible tearing of the foil resulting in contamination of the NVR plate.
the DOP test.
6.15 Noncontaminating Nylon Bag to enclose each covered
6.5 Vacuum Filtration System, consisting of a 47-mm-
NVR plate.
diameter membrane filter funnel and vacuum pump that will
6.15.1 Bags shall not contain or generate molecular or
provide a pressure of 30 kPa (250 torr) (a vacuum of 20 in.
particulate matter that could contaminate the NVR plate or
Hg). See Fig. 1.
NVR plate carrier.
6.6 Solvent Resistant Filter, 47-mm diameter, 0.2-μm pore
6.16 NVR Plate Carrier—The sealable, aluminum carrier
size (nominal) fluorocarbon.
shown in Fig. 4 has been found to be satisfactory (see Practice
6.7 Tweezers or Hemostat, stainless steel or coated with
E 1234).
TFE-fluorocarbon.
6.17 Noncontaminating Nylon Bag to protect the NVR
6.8 Beakers, low-form, glass, 250 mL, etched with an
plate carrier in 6.15. Plastic film material shall meet the safety
identification number.
and outgassing requirements for the spacecraft and spacecraft
6.9 Evaporating Dish (Petri Dish), borosilicate glass, ap-
processing facility. (See Note 4.)
proximately 15 g in mass, 60-mm diameter 3 12 mm deep, and
6.18 Drying Oven:
etched with an identification number.
6.18.1 The drying oven shall not produce molecular and
6.10 Liquid Laboratory Detergent.
particulate contaminants and shall not be used for other
6.11 Gloves, solvent compatible and resistant.
operations that could contaminate samples.
(Warning—Gloves shall be used to protect the hands from
6.19 Plate Stand—The plate stand shown in Fig. 5 has been
accidental spills of the NVR solvent and minimize contamina-
found useful for holding the NVR plate during solvent flush-
tion of exposed samples. Gloves shall be selected to meet local
ing.
safety and contamination control requirements.)
6.20 Temperature and Relative Humidity Monitors,asre-
6.12 NVR Plate, Type 316 corrosion resistant steel with an
quired, to monitor processes that are sensitive to these envi-
2 2
area of approximately 0.1 m (1 ft ). The plate shown in Fig. 2
ronments.
has been found to be satisfactory. The finish of the sampling
6.21 Vacuum oven evaporation system (Method 2), consist-
surface shall be 0.80 μm (32 μin.) or better per ANSI/ASME
ing of a vacuum oven, a two-stage vacuum pump, and vacuum
B46.1. The plate shall be electropolished and engraved with an
gage. The vacuum oven shall be controllable to within 65°C
identification number.
over an operating range of 25 to 100°C. Fig. 6 shows a typical
vacuum oven evaporation system. Two solvent traps cooled
Gelman filter funnel P/N 4012/Fisher filtrator assembly Cat. No. 09-788 and
with isopropanol/dry ice baths, collect the solvent vapors to
Millipore Cat. No. XX1504700 filtration assembly have been found to be satisfac-
prevent release into the atmosphere, protect the vacuum pump,
tory. Other suitable filtration apparatus may be used.
and allow recycling of the solvent.
Millipore Corp. Fluoropore filter Cat. No. FGLP 04700, and Gelman Sciences,
Inc. Prod. 66143 PTFE have been found to be satisfactory. Other equivalent solvent
6.22 Automatic, controlled environment (nitrogen atmo-
resistant filters may be used.
sphere) evaporator capable of controlling to a temperature of
Pioneer green nitrile gloves, Catalog No. A10-1, have been found to be
37°C (Method 3). Fig. 7 shows a typical arrangement.
satisfactory.
6.23 600-mL
...