ASTM E595-93(2003)e1

Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment

SCOPE
1.1 This test method covers a screening technique to determine volatile content of materials when exposed to a vacuum environment. Two parameters are measured: total mass loss (TML) and collected volatile condensable materials (CVCM). An additional parameter, the amount of water vapor regained (WVR), can also be obtained after completion of exposures and measurements required for TML and CVCM.  
1.2 This test method describes the test apparatus and related operating procedures for evaluating the mass loss of materials being subjected to 125°C at less than 7 X 10-3 Pa (5 X 10 -5 torr) for 24 h. The overall mass loss can be classified into noncondensables and condensables. The latter are characterized herein as being capable of condensing on a collector at a temperature of 25°C.  
Note 1—Unless otherwise noted, the tolerance on 25 and 125°C is ± 1°C and on 23°C is ± 2°C. The tolerance on relative humidity is ± 5%.  
1.3 Many types of organic, polymeric, and inorganic materials can be tested. These include polymer potting compounds, foams, elastomers, films, tapes, insulations, shrink tubings, adhesives, coatings, fabrics, tie cords, and lubricants. The materials may be tested in the "as-received" condition or prepared for test by various curing specifications.  
1.4 This test method is primarily a screening technique for materials and is not necessarily valid for computing actual contamination on a system or component because of differences in configuration, temperatures, and material processing.  
1.5 The criteria used for the acceptance and rejection of materials shall be determined by the user and based upon specific component and system requirements. Historically, TML of 1.00% and CVCM of 0.10% have been used as screening levels for rejection of spacecraft materials.  
1.6 The use of materials that are deemed acceptable in accordance with this test method does not ensure that the system or component will remain uncontaminated. Therefore, subsequent functional, developmental, and qualification tests should be used, as necessary, to ensure that the material's performance is satisfactory.  
1.7 This standard does not purport to address all of the safety problems 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.

General Information

• Status: Historical
• Publication Date: 30-Sep-2003
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.05 - Contamination

Relations

• Replaces: ASTM E595-93(1999) - Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment
• Effective Date: 01-Oct-2003
• Replaced By: ASTM E595-93(2003)e2 - Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment
• Effective Date: 01-Oct-2003
• Referred By: ASTM D6412/D6412M-99(2020) - Standard Specification for Epoxy (Flexible) Adhesive For Bonding Metallic And Nonmetallic Materials
• Effective Date: 01-Oct-2003
• Referred By: ASTM E2352-19 - Standard Practice for Aerospace Cleanrooms and Associated Controlled Environments—Cleanroom Operations
• Effective Date: 01-Oct-2003
• Referred By: ASTM E2311-04(2021) - Standard Practice for QCM Measurement of Spacecraft Molecular Contamination in Space
• Effective Date: 01-Oct-2003
• Referred By: ASTM E1559-09(2022) - Standard Test Method for Contamination Outgassing Characteristics of Spacecraft Materials
• Effective Date: 01-Oct-2003
• Referred By: ASTM E2312-11(2019) - Standard Practice for Tests of Cleanroom Materials
• Effective Date: 01-Oct-2003
• Referred By: ASTM E1997-15(2021) - Standard Practice for the Selection of Spacecraft Materials
• Effective Date: 01-Oct-2003
• Referred By: ASTM D4067-23 - Standard Classification System and Basis for Specification for Reinforced and Filled Poly(Phenylene Sulfide) (PPS) Injection Molding and Extrusion Materials Using ASTM Methods
• Effective Date: 01-Oct-2003
• Referred By: ASTM E1216-21 - Standard Practice for Sampling for Particulate Contamination by Tape Lift
• Effective Date: 01-Oct-2003
• Referred By: ASTM E2217-12(2019) - Standard Practice for Design and Construction of Aerospace Cleanrooms and Contamination Controlled Areas
• Effective Date: 01-Oct-2003
• Referred By: ASTM E1548-09(2022) - Standard Practice for Preparation of Aerospace Contamination Control Plans
• Effective Date: 01-Oct-2003
• Referred By: ASTM D6411/D6411M-99(2020) - Standard Specification for Silicone Rubber Room Temperature Vulcanizing Low Outgassing Materials
• Effective Date: 01-Oct-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
e1
Designation:E595–93 (Reapproved 2003)
Standard Test Method for
Total Mass Loss and Collected Volatile Condensable
Materials from Outgassing in a Vacuum Environment
This standard is issued under the fixed designation E595; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e NOTE—Keywords were added editorially in October 2003.
1. Scope 1.6 The use of materials that are deemed acceptable in
accordance with this test method does not ensure that the
1.1 This test method covers a screening technique to deter-
system or component will remain uncontaminated. Therefore,
mine volatile content of materials when exposed to a vacuum
subsequent functional, developmental, and qualification tests
environment. Two parameters are measured: total mass loss
should be used, as necessary, to ensure that the material’s
(TML) and collected volatile condensable materials (CVCM).
performance is satisfactory.
An additional parameter, the amount of water vapor regained
1.7 This standard does not purport to address all of the
(WVR), can also be obtained after completion of exposures
safety concerns associated with its use. It is the responsibility
and measurements required for TML and CVCM.
of the user of this standard to establish appropriate safety and
1.2 Thistestmethoddescribesthetestapparatusandrelated
health practices and determine the applicability of regulatory
operating procedures for evaluating the mass loss of materials
−3 −5
limitations prior to use.
being subjected to 125°C at less than 7 310 Pa (5 310
torr) for 24 h. The overall mass loss can be classified into
2. Referenced Documents
noncondensables and condensables. The latter are character-
2.1 ASTM Standards:
ized herein as being capable of condensing on a collector at a
E177 Practice for Use of the Terms Precision and Bias in
temperature of 25°C.
ASTM Test Methods
NOTE 1—Unless otherwise noted, the tolerance on 25 and 125°C is
2.2 ASTM Adjuncts:
61°C and on 23°C is 62°C.The tolerance on relative humidity is 65%.
Micro VCM Detailed Drawings
1.3 Many types of organic, polymeric, and inorganic mate-
3. Terminology
rials can be tested.These include polymer potting compounds,
foams, elastomers, films, tapes, insulations, shrink tubings, 3.1 Definitions:
adhesives, coatings, fabrics, tie cords, and lubricants. The
3.1.1 collected volatile condensable material, CVCM—the
materials may be tested in the “as-received” condition or quantity of outgassed matter from a test specimen that con-
prepared for test by various curing specifications.
denses on a collector maintained at a specific constant tem-
1.4 This test method is primarily a screening technique for perature for a specified time. CVCM is expressed as a
materials and is not necessarily valid for computing actual
percentage of the initial specimen mass and is calculated from
contamination on a system or component because of differ- thecondensatemassdeterminedfromthedifferenceinmassof
ences in configuration, temperatures, and material processing.
the collector plate before and after the test.
1.5 The criteria used for the acceptance and rejection of 3.1.2 total mass loss, TML—total mass of material out-
materials shall be determined by the user and based upon
gassed from a specimen that is maintained at a specified
specific component and system requirements. Historically, constant temperature and operating pressure for a specified
TML of 1.00% and CVCM of 0.10% have been used as
time. TML is calculated from the mass of the specimen as
screening levels for rejection of spacecraft materials.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction of ASTM Committee E21 on Space contactASTM Customer Service at [e-mail]. ForAnnual Book ofASTM
Simulation andApplications of SpaceTechnology and is the direct responsibility of Standards volume information, refer to the standard’s Document Summary page on
Subcommittee E21.05 on Contamination. the ASTM website.
Current edition approved Oct. 1, 2003. Published October 2003. Originally Available fromASTM International, 100 Barr Harbor Dr., PO Box C700,West
approved in 1977. Last previous edition approved in 1999 as E595–93 (1999). Conshohocken, PA 19428–2959. Order Adjunct ADJE0595.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E595–93 (2003)
measured before and after the test and is expressed as a exposure is determined. From these results and the specimen
percentage of the initial specimen mass. mass determined after vacuum exposure, the percentage WVR
3.1.3 water vapor regained, WVR—the mass of the water is obtained.
vapor regained by the specimen after the optional recondition- 4.4 Twoorthreeemptyspecimenchambersintheheaterbar
ing step. WVR is calculated from the differences in the and collector plates on the cold bar, selected for each test at
specimen mass determined after the test for TML and CVCM random, can be used as controls to ensure that uniform
and again after exposure to a 50% relative humidity atmo- cleaning procedures have been followed after each test.
sphere at 23°C for 24 h. WVR is expressed as a percentage of 4.5 Atypicaltestapparatuscanhave24specimenchambers
the initial specimen mass. with 24 associated collector plates so that a number of
specimens of different types can be tested each time the
4. Summary of Test Method
foregoing operations are conducted. Three specimen compart-
4.1 This microvolatile condensable system was developed
mentscanserveascontrolsandthreecanbeusedforeachtype
from an earlier system for determination of macrovolatile of material being tested. The total time required for specimens
condensables that required much larger samples and a longer
requiring no prior preparation is approximately 4 days. The
test. equipment should be calibrated at least once a year by using
4.2 The test specimen is exposed to 23°C and 50% relative previously tested materials as test specimens.
humidity for 24 h in a preformed, degreased container (boat) 4.6 The apparatus may be oriented in any direction as long
that has been weighed. After this exposure, the boat and as the configuration shown in Fig. 1 is maintained and bulk
specimen are weighed and put in one of the specimen com-
material does not fall from the sample holder nor obstruct the
partments in a copper heating bar that is part of the test gas-exit hole.The dimensions for critical components given in
apparatus.The copper heating bar can accommodate a number
Fig. 2 and Table 1 are provided so that apparatus constructed
ofspecimensforsimultaneoustesting.Thevacuumchamberin for the purpose of this test may provide uniform and compa-
which the heating bar and other parts of the test apparatus are
rable results.
placed is then sealed and evacuated to a vacuum of at least
−3 −5
7 310 Pa(5 310 torr).Theheatingbarisusedtoraisethe 5. Significance and Use
specimen compartment temperature to 125°C. This causes
5.1 This test method evaluates, under carefully controlled
vapor from the heated specimen to stream from the hole in the
conditions, the changes in the mass of a test specimen on
specimen compartment. A portion of the vapor passes into a
exposure under vacuum to a temperature of 125°C and the
collector chamber in which some vapor condenses on a
mass of those products that leave the specimen and condense
previously-weighedandindependentlytemperature-controlled,
on a collector at a temperature of 25°C.
chromium-plated collector plate that is maintained at 25°C.
5.2 Comparisons of material outgassing properties are valid
Each specimen compartment has a corresponding collector
at 125°C sample temperature and 25°C collector temperature
chamber that is isolated from the others by a compartmented
only. Samples tested at other temperatures may be compared
separator plate to prevent cross contamination.After 24 h, the
only with other materials which were tested at that same
test apparatus is cooled and the vacuum chamber is repressur-
temperature.
izedwithadry,inertgas.Thespecimenandthecollectorplates
5.3 The measurements of the collected volatile condensable
are weighed. From these results and the specimen mass
material are also comparable and valid only for similar
determined before the vacuum exposure, the percentage TML
and percentage CVCM are obtained. Normally, the reported
values are an average of the percentages obtained from three
samples of the same material.
NOTE 2—Itisalsopossibletoconductinfraredandotheranalyticaltests
on the condensates in conjunction with mass-loss tests. Sodium chloride
flats may be used for infrared analysis. These flats are nominally 24 mm
(1in.)indiameterby3.2mm(0.125in.)thickandaresupportededgewise
inametalholderthatfitsintothecollectorplatereceptacle.Oncompletion
of the test, the flats are placed into an infrared salt flat holder for
examination by an infrared spectrophotometer.As an alternative method,
the condensate may be dissolved from the metallic collector, the solvent
evaporated, and the residue deposited on a salt flat for infrared tests.
Sodium chloride flats shall not be used for CVCM determinations.
4.3 After the specimen has been weighed to determine the
TML, the WVR can be determined, if desired, as follows: the
specimenisstoredfor24hat23°Cand50%relativehumidity
topermitsorptionofwatervapor.Thespecimenmassafterthis
Muraca,R.F.,andWhittick,J.S.,“PolymersforSpacecraftApplications.”SRI
Project ASD-5046, NASA CR-89557, N67-40270, Stanford Research Institute, FIG. 1 Schematic of Critical Portion of Test Apparatus (Section
September 1967. A-AofFig.2)
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E595–93 (2003)
FIG. 2 Critical Portion of Test Apparatus (See Table 1 for Dimensions)
−12
collector geometry and surfaces at 25°C. Samples have been encountered in interplanetary flight (for example, 10 Pa
−14
testedatsampletemperaturesfrom50to230°Candatcollector (10 torr)).Itissufficientthatthepressurebelowenoughthat
temperatures from 1 to 30°C by this test technique. Data taken the mean free path of gas molecules be long in comparison to
atnonstandardconditionsmustbeclearlyidentifiedandshould chamber dimensions.
not be compared with samples tested at 125°C sample tem- 5.5 This method of screening materials is considered a
perature and 25°C collector temperature. conservative one. It is possible that a few materials will have
5.4 The simulation of the vacuum of space in this test acceptable properties at the intended use temperature but will
method does not require that the pressure be as low as that beeliminatedbecausetheirpropertiesarenotsatisfactoryatthe
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E595–93 (2003)
TABLE 1 Test Apparatus Dimensions (See Fig. 2)
Letter mm Tolerance in. Tolerance Notes
A B
A 6.3 60.1 0.250 60.005 diameter
A B
B 11.1 60.1 0.438 60.005 diameter
A B
C 33.0 60.1 1.300 60.005 diameter
AC
D 13.45 60.10 0.531 60.005
AC
E 9.65 60.10 0.380 60.005
AC
F 0.65 60.10 0.026 60.005
C
G 7.1 60.3 0.50 60.01
A
H 0.75 60.10 0.030 60.05 stock size
A
J 12.7 60.3 0.500 60.010
1 1
K1.6 60.8 ⁄16 6 ⁄32
7 1
L8.0 60.8 ⁄16 6 ⁄32
M 16.0 60.1 0.625 60.005 cover plate must fit snugly
5 1
N 16.0 60.8 ⁄8 6 ⁄32
1 1
P 32.0 60.8 1 ⁄4 6 ⁄32
Q 50.0 60.8 2 6 ⁄32
R 25.5 60.8 1 6 ⁄32
S0.4 60.3 0.015 60.010 half stock thickness
1 1
T 12.0 60.8 ⁄2 6 ⁄32
U 25.5 60.8 1 6 ⁄32
V 25.5 60.8 1 6 ⁄32
W 50.0 60.8 2 6 ⁄32
1 1
X6.0 60.8 ⁄4 6 ⁄32
Y 25.0 60.8 1 6 ⁄32
1 1
Z1.6 60.8 ⁄16 6 ⁄32 radius, typical
A
Critical dimensions that must be maintained for test results to be comparable.
B
Diameters must be concentric to 60.1mm(60.005 in.) for test results to be comparable.
C
Dimensions include plating thickness. Satisfactory surfaces have been produced by making substrate surface finish, 1.6-µm RMS (63-µin. RMS), highly polished,
plated with electroless nickel, 0.0127 mm (0.0005 in.) thick, and finished with electroplated chromium, 0.0051 mm (0.0002 in.) thick.
test temperature of 125°C. Also, materials that condense only bell, 260 mm (10 ⁄4 in.) in diameter, that rests on a specially
below 25°C are not detected. The user may designate addi- adapted feed-through collar, also supported by the base plate.
tional tests to qualify materials for a specific application. 6.3 The operation of the vacuum chamber system and any
5.6 The determinations of TML and WVR are affected by device for raising the vacuum bell can be automatically
the capacity of the material to gain or lose water vapor. controlled.Powertotheheatingelementmountedinthecopper
Therefore, the weighings must be accomplished under con- bars is generally controlled by variable transformers through
trolled conditions of 23°C and 50% relative humidity. temperature controllers. Recorders with an electronic icepoint
5.7 Alternatively, all specimens may be put into open glass reference junction feedback may be used to monitor the heater
vials during the 24-h temperature and humidity conditioning. bar temperatures. Aheat exchanger using a suitable fluid may
Thevialsmustbecappedbeforeremovalfromtheconditioning beusedtomaintainthecollectorplateat25°Cduringthetest.
chamber. Each specimen must be weighed within 2 min after 6.4 It is recommended that the vacuum chamber system
opening the vial to minimize the loss or absorption of water include automatic controls to prevent damage in the event of
vaporwhileexposedtoanuncontrolledhumidityenvironment. power failure or cooling fluid supply failure when in unat-
While control of humidity is not necessary at this point, the tendedoperation.Caremustbetakentopreventbackstreaming
temperature for the weighing should be controlled at 23°C, the of oil from vacuum or diffusion pumps into the vacuum
same temperature prescribed for the 24-h storage test. chamber.
6.5 The controller thermocouple should be mechanically
6. Apparatus attached to the heater bar or ring to prevent the thermocouple
from loosening over time. It is essential that the orifice of the
6.1 The apparatus used in the determination of TML and
sample heater and collector plate be aligned and checked
CVCM typically contains two resistance-heated copper bars.
regularly. A good test of alignment and stability is to run the
Generally, each bar is 650 mm (25.5 in.) in length with a
same material in every sample chamber. The results should
25-mm (1-in.) square cross section and contains twelve speci-
agree within the accuracy of the test per Se
...