ASTM D972-02(2008)

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
An American National Standard
Designation:D972–97 Designation:D972–02 (Reapproved 2008)
Standard Test Method for
Evaporation Loss of Lubricating Greases and Oils
This standard is issued under the fixed designation D 972; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the loss in mass by evaporation of lubricating greases and oils for applications
where evaporation loss is a factor. Evaporation loss data can be obtained at any temperature in the range from 100 to 150°C (210
to 300°F).
1.2The values stated in either SI units or inch-pound units shall be regarded separately as standard. The values stated in each
system may not be exact equivalents of the other; therefore each system must be used independently of the other, without
combining values in any way.
1.2 The values stated in SI units are to be regarded as standard. The values in 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.
2. Referenced Documents
2.1 ASTM Standards:
A 240/A 240M Specification for Heat-Resisting Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for
Pressure Vessels and for General Applications
D 217 Test Methods for Cone Penetration of Lubricating Grease
D 2595 Test MethodsMethod for Evaporation Loss of Lubricating Greases Over Wide-Temperature Range
E 1 Specification for ASTM Liquid-in-Glass Thermometers
3. Terminology
3.1 Definitions:
3.1.1 lubricating grease, n—a semi-fluid to solid product of a thickener in a liquid lubricant.
3.1.1.1 Discussion—The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface
tension and other physical forces. Other ingredients are commonly D 217 included to impart special properties.
3.1.2 thickener, n—in lubricating grease, a substance composed of finely - divided particles dispersed in a liquid to form the
product’s structure.
3.1.2.1 Discussion—Thickeners can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap
thickeners), which are insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that
the solid particles are extremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the
D 217 liquid lubricant.
4. Summary of Test Method
4.1 The weighed sample of lubricant in an evaporation cell is placed in a bath maintained at the desired test temperature. Heated
air is passed over its surface for 22 h. The evaporation loss is calculated from the loss in mass of the sample.
This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.G on
Lubricating Grease.
´1
Current edition approved Nov. 10, 1997. Published January 1998. Originally published as D972–48T. Last previous edition D972–91 .
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.G0.03
on Physical Tests.
Current edition approved May 1, 2008. Published July 2008. Originally approved in 1948. Last previous edition approved in 2002 as D 972–02.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 01.03.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.
D972–02 (2008)
5. Significance and Use
5.1 The loss of volatile materials from greases and oils can adversely effect the original performance characteristics of a
lubricantandthereforecouldbeasignificantfactorinevaluatingalubricantforaspecificuse.Suchvolatilescanalsobeconsidered
contaminants in the environment in which the lubricant is to be used. Correlation between results from this test method and service
performance has not been established.
5.2 The test can be run at any agreed upon temperature between 100 and 150°C (210 to 300°F).
NOTE 1—The specified flow of air, 2.58 6 0.02 g/min, (2 L/min at standard temperature and pressure), assumes dry air. It is not known that the original
work involved dry air but it has since been shown that this can be a factor in reproducibility and should be addressed. A dew point of less than 10°C
at standard temperature and pressure will be satisfactory.
NOTE 2—To determine evaporation loss at temperatures above 150°C (300°F), see Test Methods D 2595.
6. Apparatus
6.1 Evaporation Cell, (Fig. 1) as described in Annex A1.
6.2 Air Supply System, capable of supplying to the cell the required flow of air free of entrained particles. A 400-mm (16-in.)
length of 25-mm (1-in.) diameter pipe packed with glass wool has been found satisfactory for filtering the air.
6.3 Oil Bath, shown in Fig. 1a and described in Annex A1.
NOTE 3—Other constant-temperature baths may be used if they are equivalent in heat capacity and thermal gradient characteristics to the oil bath.
6.4 Thermometers—For tests at 100°C (210°F) an ASTM Thermometer having a range from 95 to 103°C (204 to 218°F) and
conforming to the requirements for Thermometer 22C–86 (22F–86) as prescribed in Specification E 1 shall be used. For tests at
temperatures above 100°C (210°F) an ASTM Precision Thermometer conforming to the requirements for Thermometer 67C–86
(67F–86) as prescribed in Specification E 1 is suitable.
6.5 Flowmeter—A rotameter calibrated to deliver air at a rate of 2.58 6 0.02 g/min between 15 and 30°C (60 and 85°F) (2
L/min at standard temperature and pressure). It shall be furnished with a needle valve and mounted as shown in Fig. 1.
7. Sampling
7.1 Eachgreasetestwillrequireapproximately20gtofillthesamplecupforasinglecupforasinglerun.Therefore,thesample
presented for analysis should be large enough to make possible the selection of a representative portion for testing. Examine the
sample for any indication of non-homogenity such as oil separation, phase changes, or gross contamination. If any abnormal
conditions are found, obtain a new sample.
FIG. 1 Evaporation Test Cell FIG. 1a Assembled Apparatus
Key mm in. Key mm in.
A 6.4 0.25 D 124/130 5.0 6 0.125
B 1830 72 E 3.2 0.125
C130.5 6 0.1 = 25 F 1.3/1.8 0.051/0.072
G 73.1 2.875
Tolerances: 60.4mm(60.0156 in.) unless otherwise noted
D972–02 (2008)
7.2 Each oil test will require at least 10 g of sample for a single run. Therefore, sufficient sample should be available to observe
any g
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