ASTM D5483-02

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An American National Standard
Designation:D5483–02
Standard Test Method for
Oxidation Induction Time of Lubricating Greases by
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Pressure Differential Scanning Calorimetry
This standard is issued under the fixed designation D 5483; 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.
1. Scope
1.1 This test method covers the determination of oxidation
inductiontimeoflubricatinggreasessubjectedtooxygenat3.5
MPa (500 psig) and temperatures between 155 and 210°C.
1.2 The values stated in SI units are to be regarded as the
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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
2 FIG. 1 PDSC Test Unit
E 473 Terminology Relating to Thermal Analysis
3. Terminology
at a regulated temperature and pressure until an exothermic
3.1 Definitions of Terms Specific to This Standard:
reaction occurs. The extrapolated onset time is measured and
3.1.1 extrapolated onset time, n—a time determined on a
reported as the oxidation induction time for the grease under
thermal curve, as the intersection of the extrapolated baseline
the specified test temperature.
and a line tangent to the oxidation exotherm constructed at its
4.2 A kinetic equation incorporated with this test method
maximum rate.
can estimate oxidation induction times at other temperatures.
3.1.2 oxidation induction time (OIT), n— the period of time
5. Significance and Use
from the first exposure to an oxidizing atmosphere until the
extrapolated onset time.
5.1 Oxidation induction time, as determined under the
3.1.3 pressure differential scanning calorimeter, (PDSC),
conditions of this test method, can be used as an indication of
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n—a differential scanning calorimeter, as defined in Terminol-
oxidation stability. This test method can be used for research
ogy E 473, that is capable of maintaining the test sample at a
and development, quality control and specification purposes.
controlled, elevated pressure.
However, no correlation has been determined between the
3.1.4 thermal curve, n—a graph of sample heat flow versus
results of this test method and service performance.
time.
6. Apparatus
4. Summary of Test Method
6.1 Pressure Differential Scanning Calorimeter (PDSC),
4
4.1 Asmall quantity of grease is weighed into a sample pan
equipped with the following items (See Fig. 1).
and placed in a test cell. The cell is heated to a specified
temperature and then pressurized with oxygen. The cell is held
3
Rhee, In-Sik, “Development of a New Oxidation Stability Test Method for
Greases Using a Pressure Differential Scanning Calorimeter (PDSC),” NLGI
Spokesman, Vol 55, No. 4, July 1991, pp. 123–132.
1 4
This test method is under the jurisdiction of ASTM Committee D02 on Available from TA Instruments, Inc., 109 Lukens Drive, New Castle, DE
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee 19720.At the time that the round robin data for this test method was generated, only
D02.O9.0E on Greases. this company manufactured equipment that met the requirements of 5.1. Subse-
Current edition approved January 10, 2002. Published March 2002. Originally quently, other companies have manufactured equipment meeting these require-
published as D 5483 – 93. Last previous edition D 5483 – 95. ments. Their use is permitted provided their performance is consistent with the
2
Annual Book of ASTM Standards, Vol 14.02. repeatability and reproducibility described in Section 10.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5483–02
FIG. 2 Calibration
the encapsulation press. Place the crimped pan onto the sample
platform in the pressure cell. Seal an empty pan in the same
manner and place it on the reference platform. Set the cell
cover in place and close the cell.
8.1.2 Open the oxygen cylinder valve slightly and set a
pressureof3.5 60.2MPa(500 625psig)onthecellinletline
withthepressureregulator.Partiallyopentheinletvalveonthe
cell and allow the pressure to slowly build up in the cell. This
FIG. 3 Sample Preparation on SFI Pan
should require approximately 2 min. Using the outlet valve,
adjust the oxygen purge rate through the flowmeter to 100 6
6.1.1 Sample Enclosure, with capability to 3.5 MPa (500
10 mL/min. The open position of these valves should remain
p
...