ASTM D2715-92(2012)
(Test Method)Standard Test Method for Volatilization Rates of Lubricants in Vacuum (Withdrawn 2017)
Standard Test Method for Volatilization Rates of Lubricants in Vacuum (Withdrawn 2017)
SIGNIFICANCE AND USE
This test method provides data for comparison of the evaporation rate of lubricants used in unshielded bearings in the space environment.
SCOPE
1.1 This test method covers the determination of the rates of volatilization of lubricants in a thermal-vacuum environment at pressures and temperatures necessary to obtain a measurable rate of evaporation, or evidence of decomposition.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
WITHDRAWN RATIONALE
This test method covered the determination of the rates of volatilization of lubricants in a thermal-vacuum environment at pressures and temperatures necessary to obtain a measurable rate of evaporation, or evidence of decomposition.
Formerly under the jurisdiction of Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants, this test method was withdrawn in December 2017. This standard is being withdrawn without replacement due to its limited use by industry.
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
Designation: D2715 − 92 (Reapproved 2012)
Standard Test Method for
Volatilization Rates of Lubricants in Vacuum
This standard is issued under the fixed designation D2715; 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 5. Apparatus
1.1 Thistestmethodcoversthedeterminationoftheratesof
5.1 Recording Vacuum Microbalance , with capacity of 1 g
volatilizationoflubricantsinathermal-vacuumenvironmentat
or more, sensitivity of 0.01 mg or less, zero stability of 0.025
pressures and temperatures necessary to obtain a measurable
mg or less for 8 h with ranges of weight change of 10 mg or
−5
rate of evaporation, or evidence of decomposition.
more, and 0.1 mg or less, capable of being pumped to 10 Pa
−7
(10 torr) or less.
1.2 The values stated in SI units are to be regarded as
5.1.1 When Procedure B for the more volatile samples is
standard. No other units of measurement are included in this
−2 −4
used, the vacuum requirement shall be 10 Pa (10 torr) or
standard.
less.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.2 Vacuum System—A pumping system capable of main-
−6 −5 −8 −7
responsibility of the user of this standard to establish appro- tainingastartingpressureof10 to10 Pa(10 to10 torr)
priate safety and health practices and determine the applica-
(5.1.1). An optically dense baffle system should be used to
bility of regulatory limitations prior to use. ensure freedom from back-streaming. A conventional bell jar
system with an oil diffusion pump, a mechanical back-up
2. Referenced Documents
pump,andanopticallydense,liquid,nitrogen-cooledbafflehas
2.1 ASTM Standards:
beenfoundsatisfactoryontheconfigurationasshowninFig.1.
E296Practice for Ionization Gage Application to Space
5.3 Furnace, with thermocouple indicator, capable of main-
Simulators
taining a constant sample temperature 63°C. All parts of this
E297Methods for Calibrating Ionization Vacuum Gage
furnace must be proved to be usable at the highest temperature
Tubes
and vacuum contemplated.
3. Summary of Test Method
5.4 Recorder, capable of recording weight changes continu-
3.1 A known quantity of specimen is placed in a thermal
ously with the balance used, to the performance specified in
vacuum balance system and the evaporated material is con- 5.1.
densed on a cold plate. The weight of the specimen is
5.5 Specimen Container, made of 300 series stainless steel
continuallyrecordedasafunctionoftimefornominalconstant
in the form of a straight cylinder with an aspect ratio of height
surface area.
to diameter of approximately 1:14. Where chemical reactions
are experienced with the container, alternative materials may
4. Significance and Use
be used.
4.1 This test method provides data for comparison of the
evaporation rate of lubricants used in unshielded bearings in
5.6 Contacting Thermocouple, touching solid or immersed
the space environment. in liquid specimens, with the leads brought out in such a way
as not to influence balance indication.
This test method is under the jurisdiction of ASTM Committee D02 on
5.7 Cold Plate—A condensing shield cooled with liquid
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
nitrogen to immobilize molecules evaporated from the lubri-
SubcommitteeD02.L0.07onEngineeringSciencesofHighPerformanceFluidsand
Solids (Formally D02.1100). cant which subtends, at least, a 160° arc from the center of the
Current edition approved April 15, 2012. Published April 2012. Originally
sample.
approved in 1968. Last previous edition approved in 2007 as D2715–92 (2007).
DOI: 10.1520/D2715-92R12.
5.8 Nude Ionization Gage, installed as described in Practice
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
E296 and calibrated as described in Methods E297.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
5.9 Optional Supplemental Equipment:
the ASTM website.
3 5.9.1 MassSpectrometer,toidentifydegassingproductsand
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. evaporating species.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2715 − 92 (2012)
FIG. 1 Apparatus for Measuring Evaporation Rates in Vacuum
5.9.2 Infrared Optical Pyrometer System, for determining ration rate material, the performance of which can be checked
the specimen temperature. This must be calibrated against the by the Langmuir equation.)
thermocouple for each material used, due to emissivity effects.
6.3 Liquid Nitrogen, commercial grade.
5.9.3 Copper Tab, on a cold plate facing the specimen, for
6.4 Helium, ACS purified grade.
X-ray analysis of the condensate.
5.9.4 Noncontact Specimen Thermocouple, calibrated
7. Specimen Preparation
against 5.5.
7.1 Remove dissolved gases from the bulk lot prior to test
5.9.5 Pressure Recording Pen, added to the recorder.
using a separate vacuum chamber. Break the vacuum in the
5.9.6 Time Derivative Computer, to report the rate directly.
chamber with helium. A large enough sample of material
shouldbedegassedinthispretreatmentsothatitwillsufficefor
6. Reagents and Materials
all anticipated test runs. A mass spectrometer can be used to
6.1 Antiwetting Agent—A low-surface tension material for
verify complete degassing.
coating the specimen container and the thermocouple. Its
7.2 If required as evidenced by creepage of lubricant in first
volatilitymustbelowenoughtocontributelessthan5%tothe
run, coat the container and the thermocouple with the anti-
evaporation rate of any sample to be tested.
wetting agent (6.1). Silicones are especially likely to require
6.2 Calibration Material—Pure compound of suitable
this precaution.
physical properties to simulate the lubricant under investiga-
tion. (N-heptadecane and bis m-(m-phenoxyphenoxy) phenyl
Freundlich, M. M., “Microbalance for Measuring Evaporation Rates in
ether have been found satisfactory. Tin provides a low evapo- Vacuum,” Vacuum, Vol 14, 1963, pp. 293–297.
D2715 − 92 (2012)
7.3 Add to the container the required amount of sample, 75 for this percentage point of the original weight. If the material
6 5 mg/cm of area exposed for evaporation. Press solids and has uniform molecular weight throughout, the rate will not
semisolids into the container with sufficient pressure to assure change with progressing evaporation. If the rate changes,
the apparent surface area approximates the real surface area. If continue measurement until the time for a single rate determi-
a coherent surface cannot be achieved, note this fact in the nation exceeds 3 h.
report.
9.9 Determine rates for several temperatures, using a fresh
sample for each determination. Temperature intervals of 25 K,
8. System Calibration
which approximate a ten-fold increase in rate, are usually
8.1 Calibrate the system in the vacuum, using one of the
suitable.
calibration materials, over the temperature range to be used,
NOTE 2—If the sample is known to be an essentially pure compound,
following the procedure shown in 9.1 – 9.8.
repetitive measurements are permissible. If such purity is merely
8.2 Theratesobtainedarecomparedwiththosepredictedby suspected, judgment may
...
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