ASTM E834-09
(Practice)Standard Practice for Determining Vacuum Chamber Gaseous Environment Using a Cold Finger
Standard Practice for Determining Vacuum Chamber Gaseous Environment Using a Cold Finger
SIGNIFICANCE AND USE
When applied in the case in which there is no test item in the vacuum chamber (such as during bake-out operations), this procedure may be used to evaluate the performance of the vacuum chamber in relation to other data from the same or other chambers given that critical parameters (for example, length of exposure, temperature of the chamber and cold finger, anisotropy, and so forth) can be related.
The procedure can be used to evaluate the effects of materials found in the residue on items placed in the vacuum chamber.
The procedure can be used to describe the effect of a prior test on the residual gases within a vacuum chamber.
By selecting the time at which the coolant is introduced into the cold finger, the environment present during a selected portion of a test can be characterized. This can be used to determine the relative efficacy of certain vacuum chamber procedures such as bake-out.
The procedure may be used to define the outgassed products of a test item that condense on the cold finger.
The procedure may be used in defining the relative cleanliness of a vacuum chamber.
In applying the results of the procedure to the vacuum chamber in general, consideration must be given to the anisotropy of the molecular fluxes within the chamber.
The procedure is sensitive to both the partial pressures of the gases that form the condensibles and the time of exposure of the cold finger at coolant temperatures.
The procedure is sensitive to any losses of sample that may occur during the various transfer operations and during that procedure wherein the solvent is evaporated by heating it on a steam bath.
Note 1—Reactions between solvent and condensate can occur and would affect the analysis.
SCOPE
1.1 This practice covers a technique for collecting samples of materials that are part of the residual gas environment of an evacuated vacuum chamber. The practice uses a device designated as a “cold finger” that is placed within the environment to be sampled and is cooled so that constituents of the environment are retained on the cold-finger surface.
1.2 The practice covers a method for obtaining a sample from the cold finger and determining the weight of the material removed from the cold finger.
1.3 The practice contains recommendations as to ways in which the sample may be analyzed to identify the constituents that comprise the sample.
1.4 By determining the species that constitute the sample, the practice may be used to assist in defining the source of the constituents and whether the sample is generally representative of samples similarly obtained from the vacuum chamber itself.
1.5 This practice covers alternative approaches and usages to which the practice can be put.
1.6 The degree of molecular flux anisotropy significantly affects the assurance with which one can attribute characteristics determined by this procedure to the vacuum chamber environment in general.
1.7 The temperature of the cold finger significantly affects the quantity and species of materials collected.
1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.9 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. For specific warning statements, see Section 8.
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Designation: E834 − 09
StandardPractice for
Determining Vacuum Chamber Gaseous Environment Using
1
a Cold Finger
This standard is issued under the fixed designation E834; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope bility of regulatory limitations prior to use. For specific
warning statements, see Section 8.
1.1 This practice covers a technique for collecting samples
of materials that are part of the residual gas environment of an
2. Referenced Documents
evacuated vacuum chamber. The practice uses a device desig-
2
2.1 ASTM Standards:
nated as a “cold finger” that is placed within the environment
E177Practice for Use of the Terms Precision and Bias in
to be sampled and is cooled so that constituents of the
ASTM Test Methods
environment are retained on the cold-finger surface.
1.2 The practice covers a method for obtaining a sample
3. Terminology
fromthecoldfingeranddeterminingtheweightofthematerial
3.1 pretest cold finger sample residue mass, M—themassof
removed from the cold finger. i
material collected from the cold finger during the pretest
1.3 The practice contains recommendations as to ways in
operation and as measured by the techniques specified in
which the sample may be analyzed to identify the constituents
Section 9. The mass is based on a sample volume of 50 mL.
that comprise the sample.
3.2 posttest stock sample residue mass, M—the mass of
f
1.4 By determining the species that constitute the sample,
residue in a sample collected from the cold finger during the
the practice may be used to assist in defining the source of the
posttest operation and as measured by the technique specified
constituentsandwhetherthesampleisgenerallyrepresentative
in Section 9.The mass is based on a sample volume of 50 mL.
of samples similarly obtained from the vacuum chamber itself.
3.3 pretest stock sample residue mass, S—the mass of
i
1.5 This practice covers alternative approaches and usages
residue in a sample of the solvent (used to obtain the pretest
to which the practice can be put.
cold finger sample) as measured by the technique specified in
Section 9. The mass is based on a sample volume of 50 mL.
1.6 The degree of molecular flux anisotropy significantly
3.4 posttest stock sample residue mass, S— the mass of
affects the assurance with which one can attribute characteris-
f
tics determined by this procedure to the vacuum chamber residue in a sample of the solvent (used to obtain the posttest
cold finger sample) as measured by the technique specified in
environment in general.
Section 9. The mass is based on a sample volume of 50 mL.
1.7 The temperature of the cold finger significantly affects
3.5 cold finger—the device that is used in collecting the
the quantity and species of materials collected.
sample of the residual gases in an evacuated vacuum chamber
1.8 The values stated in SI units are to be regarded as
(see Fig. 1).
standard. No other units of measurement are included in this
3.6 CFR—theresiduecollectedbythecoldfingerduringthe
standard.
vacuum exposure given in milligrams.
1.9 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Practice
responsibility of the user of this standard to establish appro-
4.1 The cold-finger technique provides a method for char-
priate safety and health practices and determine the applica-
acterizing the ambiance in a vacuum chamber when the
chamber is being operated with or without a test item.
1
This practice is under the jurisdiction of ASTM Committee E21 on Space
Simulation andApplications of SpaceTechnology and is the direct responsibility of
2
Subcommittee E21.05 on Contamination. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2009. Published December 2009. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1981. Last previous edition approved in 2004 as E834–04. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0834-09. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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E834 − 09
4.6 Both the pretest and posttest samples are placed in
previouslycleanedandweighedevaporatingdishes.Thedishes
containing the samples are placed on a steam bath and the
solvent is evaporated. The dishes containing the residue are
then weighed using an analytical balance. The samples of the
solvent are similarly handled and any residue
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:E834–04 Designation:E834–09
Standard Practice for
Determining Vacuum Chamber Gaseous Environment Using
1
a Cold Finger
This standard is issued under the fixed designation E834; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers a technique for collecting samples of materials that are part of the residual gas environment of an
evacuated vacuum chamber. The practice uses a device designated as a “cold finger” that is placed within the environment to be
sampled and is cooled so that constituents of the environment are retained on the cold-finger surface.
1.2 The practice covers a method for obtaining a sample from the cold finger and determining the weight of the material
removed from the cold finger.
1.3 The practice contains recommendations as to ways in which the sample may be analyzed to identify the constituents that
comprise the sample.
1.4 By determining the species that constitute the sample, the practice may be used to assist in defining the source of the
constituents and whether the sample is generally representative of samples similarly obtained from the vacuum chamber itself.
1.5 This practice covers alternative approaches and usages to which the practice can be put.
1.6 The degree of molecular flux anisotropy significantly affects the assurance with which one can attribute characteristics
determined by this procedure to the vacuum chamber environment in general.
1.7 The temperature of the cold finger significantly affects the quantity and species of materials collected.
1.8
1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.9 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. For specific warning statements, see Section 8.
2. Referenced Documents
2
2.1 ASTM Standards:
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
3. Terminology
3.1 pretest cold finger sample residue mass, M—themassofmaterialcollectedfromthecoldfingerduringthepretestoperation
i
and as measured by the techniques specified in Section 9. The mass is based on a sample volume of 50 mL.
3.2 posttest stock sample residue mass, M—the mass of residue in a sample collected from the cold finger during the posttest
f
operation and as measured by the technique specified in Section 9. The mass is based on a sample volume of 50 mL.
3.3 pretest stock sample residue mass, S—the mass of residue in a sample of the solvent (used to obtain the pretest cold finger
i
sample) as measured by the technique specified in Section 9. The mass is based on a sample volume of 50 mL.
3.4 posttest stock sample residue mass, S—themassofresidueinasampleofthesolvent(usedtoobtaintheposttestcoldfinger
f
sample) as measured by the technique specified in Section 9. The mass is based on a sample volume of 50 mL.
3.5 cold finger—thedevicethatisusedincollectingthesampleoftheresidualgasesinanevacuatedvacuumchamber(seeFig.
1).
3.6 CFR—the residue collected by the cold finger during the vacuum exposure given in milligrams.
1
This practice is under the jurisdiction of ASTM Committee E21 on Space Simulation and Applications of Space Technology and is the direct responsibility of
Subcommittee E21.05 on Contamination.
Current edition approved Sept. 1, 2004. Published September 2004. Originally approved in 1981. Last previous edition approved in 1998 as E834–81 (1998). DOI:
10.1520/E0834-04.
Current edition approved Nov. 1, 2009. Published December 2009. Originally approved in 1981. Last previous edition approved in 2004 as E834–04. DOI:
10.1520/E0834-09.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
E834–09
FIG. 1 Typical Cold Finger Assembly
4. Summary of Practice
4.1 The cold-finger technique prov
...
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