ASTM D8120-17

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D8120 −17
Standard Test Method for
Ferrous Debris Quantification
This standard is issued under the fixed designation D8120; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method describes a means for quantitative
D4057 Practice for Manual Sampling of Petroleum and
determination of the concentration of ferrous debris in lubri-
Petroleum Products
cants and greases.
D4177 Practice for Automatic Sampling of Petroleum and
1.2 This test method provides a determination of the con-
Petroleum Products
centration of ferrous debris in the lubricant or grease from a
D5185 Test Method for Multielement Determination of
nominal 0 mg/kg to 10 000 mg/kg (1 % by mass) or greater.
Used and Unused Lubricating Oils and Base Oils by
Inductively Coupled Plasma Atomic Emission Spectrom-
1.3 This test method is applicable to all types of lubricating
etry (ICP-AES)
fluids (API Group I-V) and greases sampled from machinery
D5854 Practice for Mixing and Handling of Liquid Samples
and other mechanical equipment, including reciprocating en-
of Petroleum and Petroleum Products
gine oils, turbine oils, hydraulic oils, gear oils, and bearing
D6595 Test Method for Determination of Wear Metals and
greases.
Contaminants in Used Lubricating Oils or Used Hydraulic
1.4 This test method describes a means by which a sample
Fluids by Rotating Disc ElectrodeAtomic Emission Spec-
of lubricant or grease is placed in a magnetometer apparatus,
trometry
which determines the concentration of ferrous debris and
D7669 Guide for Practical Lubricant Condition Data Trend
provides these readings directly to the operator without further
Analysis
calculation.
D7690 Practice for Microscopic Characterization of Par-
ticles from In-Service Lubricants by Analytical Ferrogra-
1.5 This test method is applicable to in-service lubricants
phy
and greases at any stage of degradation.
D7718 Practice for Obtaining In-Service Samples of Lubri-
1.6 The values stated in SI units are to be regarded as cating Grease
standard. No other units of measurement are included in this D7720 Guide for Statistically Evaluating Measurand Alarm
standard. Limits when Using Oil Analysis to Monitor Equipment
and Oil for Fitness and Contamination
1.7 This standard does not purport to address all of the
D7874 Guide for Applying Failure Mode and Effect Analy-
safety concerns, if any, associated with its use. It is the
sis (FMEA) to In-Service Lubricant Testing
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
3. Terminology
bility of regulatory limitations prior to use.
3.1 Definitions of Terms Specific to This Standard:
1.8 This international standard was developed in accor-
3.1.1 ferrous debris concentration, n—the concentration,
dance with internationally recognized principles on standard-
expressedasmilligramsperkilogramorpercentage(percentby
ization established in the Decision on Principles for the
mass) of ferrous debris in a sample of lubricant across all
Development of International Standards, Guides and Recom-
particle size ranges of the debris, from dissolved to large
mendations issued by the World Trade Organization Technical
ferrous debris particles in the millimeter size range. Note that
Barriers to Trade (TBT) Committee.
such ferrous debris may exist in a matrix in the lubricant such
as when organically combined or as part of a steel alloy.
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 D02.96.06 on Practices and Techniques for Prediction and Determi- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
nation of Microscopic Wear and Wear-related Properties. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved June 1, 2017. Published July 2017. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D8120-17. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8120 − 17
3.1.2 sample, n—a portion of in-service oil or grease drawn susceptibility of the lubricant is determined. This magnetic
directly from the machinery without further processing. susceptibility is then correlated to the concentration of ferrous
debris in the lubricant by means of the known magnetic
4. Summary of Test Method
susceptibility of such debris.
4.1 Asample of in-service lubricant or grease is taken from
8. Reagents and Materials
the machinery or equipment and transferred into a suitable
measurementreceptacle.Themanufacturer’srecommendations
8.1 A disposable, plastic sample container of sufficient
should be followed for preferred holders or receptacles but
capacity to perform the measurement. Consult the instrument
typical container formats include sample bottles, syringes, and
manufacturer’s instructions for the recommended containers
grease samplers. The sample holder is then manually placed
and method of sample presentation.
inside an indicated empty measurement chamber of a magne-
8.2 At least two calibration standards of uniformly sus-
tometer apparatus. Some instruments may require the sample
pended ferrous material that provide equivalent magnetic
holder to be removed before the measurement is complete and
susceptibilities within the lower and upper quartiles of the
will prompt accordingly. By measuring the difference in signal
selected measurement range. These standards may consistent
between the filled chamber and the empty chamber, the
of, for example, suspended M50 bearing steel in oil or a resin
concentration of ferrous debris in milligrams per kilogram or
matrix and are to be used as check standards for the purposes
percent by mass is determined.
of confidence testing. An optional third standard for the
mid-range point is useful but not essential. Again, consult the
5. Significance and Use
manufacturer’s instructions for recommended practices regard-
5.1 By quantifying the concentration of total ferrous debris,
ing (re)calibration and check intervals.
this test method provides a direct indication of wear in the
8.3 A lint-free, oil-absorbent material should be used to
machinery by enabling the user to pinpoint when there is a
clean the apparatus. Some suitable examples would be poly-
deviationfromthenormalbuildupofferrousdebrisshedbythe
propylene industrial wipes or clean cotton shop rag.
machinery or when the concentration of ferrous debris has
exceeded safe operating limits. Specific guidance regarding
such procedures may be found in Guides D7669, D7720, and 9. Hazards
D7874.
9.1 All precautions in the sampling and handling of in-
5.2 This test method can be performed on-site and can be service lubricant samples should be followed as appropriate.
utilized as a particle-size insensitive, minimum sample prepa-
Please see Practices D4057, D4177,or D7718 for guidance on
ration alternative to laboratory-based screening for abnormal this point.
machinery conditions due to the presence of wear debris by
means of ferrography as described in Practice D7690,or
10. Sampling, Test Specimens, and Test Units
elemental analysis methods such as atomic emission
10.1 A sample of the liquid or grease should be obtained
spectrometry, described in Test Methods D5185 and D6595.
following the guidelines described in Practices D4057, D4177,
or D7718. A representative portion of the lubricant and of
6. Interferences
sufficientvolumetofillthemeasurementbottle,syringe,andso
6.1 This test method provides a measure of the concentra-
forth should be collected in a clean, dry container. Care should
tion of ferrous debris by measuring the magnetic susceptibility
be taken to ensure that the portion collected is as representative
of the sample under test. Non-ferrous debris, which is ferro-
of the in-service fluid or grease as possible. Avoid sampling
magnetic (such as nickel or cobalt), may be reported as ferrous
from the bottom of sumps or other similar dead spots, where
debris using this test method.
deposits may have built up over time. Consult the relevant
ASTM practices noted above for more guidance on suitable
7. Apparatus
samplingpoints.Also,checkthatthesampleisatatemperature
7.1 The core apparatus consists of a solenoid-style magne-
compatible with the specifications of the sample container
tometer with an inner coil diameter of sufficient size to
before being drawn for analysis.
accommodate the sample holder. Standard in-service oil analy-
10.2 Inspect the collected portion for homogeneity and if in
sis sample bottles (2 oz capacity), syringes (3 mL capacity),
doubt, have it re-homogenized to ensure that a representative
and grease pots (5 mLcapacity) serve as sample holders. Other
sample can be measured in the magnetometer. Follow Practice
sample holders can be a
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