ASTM D5483-05(2010)
(Test Method)Standard Test Method for Oxidation Induction Time of Lubricating Greases by Pressure Differential Scanning Calorimetry
Standard Test Method for Oxidation Induction Time of Lubricating Greases by Pressure Differential Scanning Calorimetry
SIGNIFICANCE AND USE
Oxidation induction time, as determined under the conditions of this test method, can be used as an indication of oxidation stability. This test method can be used for research and development, quality control and specification purposes. However, no correlation has been determined between the results of this test method and service performance.
SCOPE
1.1 This test method covers the determination of oxidation induction time of lubricating greases subjected to oxygen at 3.5 MPa (500 psig) and temperatures between 155 and 210°C.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
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.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D5483 − 05(Reapproved 2010)
Standard Test Method for
Oxidation Induction Time of Lubricating Greases by
Pressure Differential Scanning Calorimetry
This standard is issued under the fixed designation D5483; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.4 thermal curve, n—a graph of sample heat flow versus
time.
1.1 This test method covers the determination of oxidation
induction time of lubricating greases subjected to oxygen at
4. Summary of Test Method
3.5 MPa (500 psig) and temperatures between 155 and 210°C.
4.1 Asmall quantity of grease is weighed into a sample pan
1.2 The values stated in SI units are to be regarded as
and placed in a test cell. The cell is heated to a specified
standard. The values given in parentheses are for information
temperature and then pressurized with oxygen. The cell is held
only.
at a regulated temperature and pressure until an exothermic
1.3 This standard does not purport to address all of the
reaction occurs. The extrapolated onset time is measured and
safety concerns, if any, associated with its use. It is the
reported as the oxidation induction time for the grease under
responsibility of the user of this standard to establish appro-
the specified test temperature.
priate safety and health practices and determine the applica-
4.2 A kinetic equation incorporated with this test method
bility of regulatory limitations prior to use.
can estimate oxidation induction times at other temperatures.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 Oxidation induction time, as determined under the
E473 Terminology Relating to Thermal Analysis and Rhe-
conditions of this test method, can be used as an indication of
ology
oxidation stability. This test method can be used for research
and development, quality control and specification purposes.
3. Terminology
However, no correlation has been determined between the
3.1 Definitions of Terms Specific to This Standard:
results of this test method and service performance.
3.1.1 extrapolated onset time, n—a time determined on a
thermal curve, as the intersection of the extrapolated baseline
6. Apparatus
and a line tangent to the oxidation exotherm constructed at its
6.1 Pressure Differential Scanning Calorimeter (PDSC),
maximum rate.
equipped with the following items (see Fig. 1).
3.1.2 oxidation induction time (OIT), n— the period of time
NOTE 1—At the time that the round robin data for this test method was
from the first exposure to an oxidizing atmosphere until the
generated, only TA Instruments manufactured equipment that met the
extrapolated onset time.
requirements of 5.1. Subsequently, other companies have manufactured
equipment meeting these requirements. Their use is permitted provided
3.1.3 pressure differential scanning calorimeter, (PDSC),
their performance is consistent with the repeatability and reproducibility
n—a differential scanning calorimeter, as defined in Terminol-
described in Section 10.
ogy E473, that is capable of maintaining the test sample at a
6.1.1 Sample Enclosure, with capability to 3.5 MPa (500
controlled, elevated pressure.
psig)at210°Candpressuregaugegraduatedatintervalsof200
kPa (28.6 psi) or less.
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.09.0E on Oxidation of Greases. Rhee, In-Sik, “Development of a New Oxidation Stability Test Method for
Current edition approved Oct. 1, 2010. Published November 2010. Originally Greases Using a Pressure Differential Scanning Calorimeter (PDSC),” NLGI
approved in 1993. Last previous edition approved in 2005 as D5483–05. DOI: Spokesman, Vol 55, No. 4, July 1991, pp. 123–132.
10.1520/D5483-05R10. The sole source of supply of the apparatus known to the committee at this time
For referenced ASTM standards, visit the ASTM website, www.astm.org, or isTAInstruments, Inc., 109 Lukens Drive, New Castle, DE 19720. If you are aware
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM of alternative suppliers, please provide this information to ASTM International
Standards volume information, refer to the standard’s Document Summary page on Headquarters.Your comments will receive careful consideration at a meeting of the
the ASTM website. responsible technical committee, which you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5483 − 05 (2010)
from 157.4 6 0.2°C (see Note 4), correct the difference by
using either the hardware or software calibration procedure
described in the manufacturer’s instruction manual. If the
hardware calibration procedure is used, the temperature cor-
rection should be performed under 3.5 MPa (500 psig) oxygen
pressure with a 100 mL/min purge rate. A typical melting
calibration curve is shown in Fig. 2.
NOTE 4—The melting temperature of indium is 156.6°C at atmospheric
pressure, but has been found to be elevated to 157.4°C under the
conditions of this test method, 3.5 MPa (500 psig) of oxygen.
8.2 Temperature Controller Calibration:
8.2.1 Remove both the sample pan and the reference pan
from the cell, then close the cell. Slowly pressurize the cell
with 3.5 6 0.2 MPa (500 6 25 psig) oxygen and adjust the
FIG. 1 PDSC Test Unit
purge rate to 100 6 10 mL/min using the cell outlet valve.
Select the desired test temperature (either 210, 180, or 155°C).
8.2.2 Program the cell to maintain the selected test tempera-
6.2 Thermal Analyzer.
ture. If, after 10 min, the displayed cell temperature differs by
6.3 Aluminum Sample Solid Fat Index (SFI), pan (see Note
morethan 60.2°Cfromtheselectedtemperature,slowlyadjust
2).
the temperature controller until they agree. After making an
6.4 Oxidation Stability Software. adjustment, wait at least 5 min to make certain that the
temperature is stable before continuing.
6.5 Calibration Software.
8.2.3 Some of the newest instruments do not need this step
6.6 Flowmeter, with a capacity of at least 200 mL/min.
due to their automatic calibration system. Therefore, the
6.7 Sample Encapsulation Press.
controlthermocouplecalibarationshouldbeperformedaccord-
ing to the instrument’s manual.
NOTE 2—It has been found that grease samples can be prepared with
more consistent surface areas using SFI pans as compared to flat bottom
8.3 Cell Base Pressure Gauge Calibration—The calibration
pans, resulting in better reproducibility.
should be conducted using a calibrated pressure transducer or
NOTE 3—See Fig. 1 for a diagram of a typical test unit.
a previously calibrated gauge according to the pressure cell
manufacturer’s instructions.
7. Reagents and Materials
7.1 Oxygen, extra dry, of not less than 99.5 % purity by
9. Procedure
volume. (Warning—Oxidizer. Gas under pressure. In addition
to other precautions, use stainless steel or copper tubing which 9.1 Before starting a test, the control thermocouple calibra-
tion shall be conducted at the test temperature (either 210, 180,
is compatible with oxygen, and pressure gauges which are
designated for use with oxygen.) or 155°C) according to 8.2.1 and 8.2.2.When the test tempera-
ture is not known, the calibration should be conducted at
7.2 Indium, of not less than 99.9 % purity by mass.
210°C. Ignore this step if the instrument already has an
automatic temperature controller calibration system.
8. Calibration
9.2 Weigh2.0 60.1mgofgreaseintoasamplepan.Spread
8.1 Sample Temperature Calibration:
the sample evenly upon the flat portion. Do not spill any of the
8.1.1 Weigh approximately 10 mg of indium into an alumi-
sample into the trough portion of the pan (See Fig. 3).
num sample pan, insert a lid and crimp the lid to the pan using
the encapsulation press. Place the crimped pan onto the sample
NOTE 5—Examples of suitable and poor sample on pan patterns are
platform in the pressure cell. Seal an empty pan in the same
shown in Fig. 3.
manner and place it on the reference platform. Set the cell
9.3 Place the uncovered pan containing the sample onto the
cover in place and close the cell.
platform of the cell according to the PDSC manufacturer’s
8.1.2 Open the oxygen cylinder valve slightly and set a
instructions for placing the sample pan. Place an empty pan of
pressureof3.5 60.2MPa(500 625psig)onthecellinletline
the same configuration onto the cell platform according to the
withthepressure
...
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