ASTM D7919-14

Standard Guide for Filter Debris Analysis (FDA) Using Manual or Automated Processes

SIGNIFICANCE AND USE
5.1 This guide is intended to provide machinery maintenance and monitoring personnel with a guideline for performing filter debris analysis as a means to determine machine condition. Correlating the filter contaminants to ‘normal’ and ‘abnormal’ lube system operation provides early indication of a contaminant or component wear related lube system problem. Analysis of the contaminant collected within the lube filter element provides a tool to identify the failure mode, its rate of progression, and the source of the contamination.  
5.2 FDA differs from traditional oil analysis in that the filter is sampled instead of the fluid. Debris from the filter is removed for analysis. FDA is an effective means of monitoring equipment wear because the wear history is efficiently captured in the filter matrix. Typically, more than 95 % of all released metal particles larger than the filter pore size are captured in the filter (1).5 In addition, other types of particulate contamination, including seal wear material and environmental contaminations are captured, which can also provide diagnostic information.
SCOPE
1.1 This guide pertains to removal and analysis techniques to extract debris captured by in-service lubricant and hydraulic filters and to analyze the debris removed.  
1.2 This guide suggests techniques to remove, collect and analyze debris from filters in support of machinery health condition monitoring.  
1.3 Debris removal techniques range from manual to automated.  
1.4 Analysis techniques vary from visual, particle counting, microscopic, x-ray fluorescence (XRF), atomic emission spectroscopy (AES), and scanning electron microscopy energy dispersive x-rays (SEMEDX).  
1.5 This guide is suitable for use with the following filter types: screw on, metal mesh, and removable diagnostic layer filters.  
1.6 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.

General Information

• Status: Historical
• Publication Date: 30-Apr-2014
• ICS: 23.100.60 - Filters, seals and contamination of fluids
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.96.06 - Practices and Techniques for Prediction and Determination of Microscopic Wear and Wear-related Properties

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7919 − 14
Standard Guide for
Filter Debris Analysis (FDA) Using Manual or Automated
Processes
This standard is issued under the fixed designation D7919; 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.
INTRODUCTION
Typically, main lubrication systems incorporate in-system filters to maintain an appropriate
lubricant cleanliness level during operation. Since the lubrication filter element removes and retains
a major portion of the solid contamination in the lubrication system, evaluation of the debris captured
withinthefilterelementaidsinthedeterminationofmachineconditionandrootcauseanalysis(RCA).
The past decade has seen more widespread use of filter debris analysis (FDA) as a condition-
monitoring tool to detect and analyze abnormal contaminant ingression into the lube system and
predict lube system component wear. This is in part due to the increased use of finer filtration in
machinery which results in a decrease of wear debris available for detection by traditional sampled oil
analysis. The U. S. military and other militaries around the world as well as Original Equipment
ManufacturershaveadoptedFDAtechniques.Commercialin-serviceoillaboratoriesarealsoutilizing
a wide range of FDA techniques, from manual to automated. It is necessary to provide a guide to
improve analysis and comparison of data.
1. Scope priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 This guide pertains to removal and analysis techniques
to extract debris captured by in-service lubricant and hydraulic
2. Referenced Documents
filters and to analyze the debris removed.
1.2 This guide suggests techniques to remove, collect and 2.1 ASTM Standards:
analyze debris from filters in support of machinery health D5185 Test Method for Multielement Determination of
condition monitoring.
Used and Unused Lubricating Oils and Base Oils by
Inductively Coupled Plasma Atomic Emission Spectrom-
1.3 Debris removal techniques range from manual to auto-
etry (ICP-AES)
mated.
D6595 Test Method for Determination of Wear Metals and
1.4 Analysis techniques vary from visual, particle counting,
Contaminants in Used Lubricating Oils or Used Hydraulic
microscopic, x-ray fluorescence (XRF), atomic emission spec-
Fluids by Rotating Disc ElectrodeAtomic Emission Spec-
troscopy (AES), and scanning electron microscopy energy
trometry
dispersive x-rays (SEMEDX).
D7669 Guide for Practical Lubricant Condition Data Trend
1.5 This guide is suitable for use with the following filter
Analysis
types: screw on, metal mesh, and removable diagnostic layer
D7684 Guide for Microscopic Characterization of Particles
filters.
from In-Service Lubricants
1.6 This standard does not purport to address all of the
D7685 Practice for In-Line, Full Flow, Inductive Sensor for
safety concerns, if any, associated with its use. It is the
Ferromagnetic and Non-ferromagnetic Wear Debris De-
responsibility of the user of this standard to establish appro-
termination and Diagnostics for Aero-Derivative and Air-
craft Gas Turbine Engine Bearings
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
mittee D02.96.06 on Practices and Techniques for Prediction and Determination of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Microscopic Wear and Wear-related Properties. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved May 1, 2014. Published June 2014. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7919-14. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7919 − 14
D7690 Practice for Microscopic Characterization of Par- ing filter debris analysis as a means to determine machine
ticles from In-Service Lubricants by Analytical Ferrogra- condition. Correlating the filter contaminants to ‘normal’ and
phy ‘abnormal’ lube system operation provides early indication of
D7720 Guide for Statistically Evaluating Measurand Alarm acontaminantorcomponentwearrelatedlubesystemproblem.
Limits when Using Oil Analysis to Monitor Equipment Analysis of the contaminant collected within the lube filter
and Oil for Fitness and Contamination element provides a tool to identify the failure mode, its rate of
D7898 Practice for Lubrication and Hydraulic Filter Debris progression, and the source of the contamination.
Analysis (FDA) for Condition Monitoring of Machinery
5.2 FDAdiffers from traditional oil analysis in that the filter
2.2 Other Documents:
is sampled instead of the fluid. Debris from the filter is
TTCP-AER-TP3-TR01-2010 Filter Debris Analysis Guide,
removed for analysis. FDAis an effective means of monitoring
July 2010, published by The Technical Cooperation Pro-
equipmentwearbecausethewearhistoryisefficientlycaptured
gram (TTCP)
in the filter matrix. Typically, more than 95 % of all released
SAE AIR1828 Guide to Oil System Monitoring in Aircraft
metalparticleslargerthanthefilterporesizearecapturedinthe
Gas Turbine Engines
filter (1). In addition, other types of particulate contamination,
includingsealwearmaterialandenvironmentalcontaminations
3. Terminology
are captured, which can also provide diagnostic information.
3.1 Definitions:
3.1.1 lubricant condition monitoring, n—a field of technical
6. Interferences
activity in which selected physical parameters associated with
6.1 Time-on-Filter Information—If the time-on-filter is not
an operating machine are periodically or continuously sensed,
known, it is not possible to set limits for rate and severity of
measured, and recorded for the interim purpose of reducing,
particulate generation.
analyzing, comparing, and displaying the data and information
6.2 Analysis Techniques—To compare filter debris from like
so obtained and for the ultimate purpose of using interim result
to support decisions related to the operation and maintenance equipment, the same filter extraction and analysis techniques
must be utilized. Note some of the techniques in this guide are
of the machine.
quite subjective such as visual analysis and manual extraction,
3.1.2 machinery health, n—a qualitative expression of the
which makes interpretation of results subjective.
operational status of a machine sub-component, component, or
entire machine, used to communicate maintenance and opera-
6.3 Operating Conditions—Machine operational intensity
tional recommendations or requirements in order to continue impacts how quickly a component wears and how rapidly a
operation, schedule maintenance, or take immediate mainte-
fault progresses. Similar equipment operating under different
nance action.
conditions can generate different wear and be exposed to
different contaminants. A relevant indicator of machine usage
3.1.3 prognostics, n—a forecast of the condition or remain-
must be included in any trend and limit calculations. (See
ing usable life of a machine, fluid, or component part.
Guides D7669 and D7720.) The selected usage indicator must
3.1.4 remaining useful life, n—a subjective estimate based
reflect actual machine usage, that is, life consumed for
upon observations, or average estimates of similar items,
example, stop/start cycles, megawatt hours, hours of use, or
components, or systems, or a combination thereof, of the
fuel consumption.
number of remaining time that an item, component, or system
6.4 Maintenance Practices—Care should be taken during
is estimated to be able to function in accordance with its
intended purpose before replacement. removalofthefiltertoensurethatmaintenancepracticesdonot
contaminate the filter.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 filter debris analysis (FDA), n—the analysis of debris
7. Procedures
specifically extracted from a system filter for the purpose of
determining the health of the oil-wetted components within 7.1 Typically, main lubrication systems incorporate in-
that system or the source of significant contaminants. system filters to maintain an appropriate lubricant cleanliness
level during operation. The filter is incorporated either in the
4. Summary of Guide
pressure line after the main lubricant pump or on the scavenge
linepriortothelubricanttank.Filterelementsarefull-flowand
4.1 This guide provides practical guidance on filter debris
provide a coherent surface for capturing contamination in the
analysis of in-service lubricant filters. Various techniques for
lubricant. The porosity of the filtration medium can be opti-
debris removal, collection, and analysis are presented with
mized for filtration efficiency, subject to the desired filter
their associated benefits and limitations.
element service life.
5. Significance and Use
7.2 Filter Media—Several filter media types are presented
5.1 This guide is intended to provide machinery mainte-
that are suitable for FDA.
nance and monitoring personnel with a guideline for perform-
3 5
Available from Technical Cooperation Program (TTCP), http:// The boldface numbers in parentheses refer to the list of references at the end of
www.acq.osd.mil/ttcp/index.html. this standard.
D7919 − 14
7.2.1 Metal Mesh Filters—These filters are common in can produce some limited information where procedures are
engine and gearbox applications. Any of the debris extraction strictly adhered to and where other techniques may not be
methods discussed in 7.3 can be utilized. practical.
7.2.2 Removable Diagnostic Layer—Some lubrication filter 7.3.2 Ultrasonic Agitation—Ultrasonic agitation improves
elements are fabricated with a removable (pull-out) diagnostic the debris extraction from a filter element. The filter is
layer, comprised of a porous medium layer. Fig. 1 depicts an submerged in a solvent and exposed to ultrasonic waves for a
enginelubefilterelementwithadiagnosticlayer.Typically,the specified period of time. The solvent should be compatible
porosity of the diagnostic layer allows for efficient retention of with the component oil. Note some reusable filter elements
larger size debris (50+ µm) of diagnostic interest in engine cannot be cleaned using ultrasonic baths as damage to the
lubrication systems (2). Since most porous media used in element filter media may result. The debris is then separated
diagnostic layers are comprised of random fiber matrices, the from the solvent as in 7.3.1.
‘diagnostic’layer exhibits lower, but significant, efficiencies in 7.3.3 Automated—Particle recovery from filters can be per-
retaining contamination in the smaller size ranges. A primary formed automatically and efficiently using an automated filter-
advantage of the diagnostic layer is that it allows for a range of washing instrument. An automated system is available that
debris analysis from simple on-site visual or microscopic automatically counts, sizes and discriminates between ferrous
examination to more extensive laboratory analysis for deter- and non-ferrous particles, prepares a patch and provides
mining the chemical elemental composition of the debris. associated elemental and alloy data utilizing its internal x-ray
7.2.3 Reusable Filters—Some filters are reusable and fluorescence (XRF) spectrometer. The automated FDA instru-
should be treated as a serviceable part. The filter element ment provides a repeatable process by incorporating an auto-
manufacturer should be consulted to determine appropriate mated filter back-washing fluid circuit utilizing a pulsed
method to extract debris and to determine which tests are air/fluid mixture to remove up to 95 % of retained debris from
required to ensure integrity of the filter for reuse. the filter (1). As the filter is backwashed, debris particles flow
7.2.4 Canister Filters (Screw-on Cartridge Filter)— through a wear debris sensor (Fig. 2) and are deposited on a
Cartridgefiltersarecommonindieselapplications.Ifmanually membrane patch. See Figs. 3 and 4, and 7.4. The patch is then
cleaning a canister filter, the outer casing may need to be cut analyzed by an internal XRF spectrometer for elemental and
opentorevealthefilterelementforprocessing.Dedicatedfilter alloy determination. The patch may also be analyzed by other
cutters are available that shear the canister open rather than means such as a microscopic analysis, SEM/EDXRF, or
sawing it, which minimizes any metallic contaminant ingress individualparticleanalysis.See7.5.Thisautomatedtechnique,
resultingfromtheopeningprocess.Notethereisthepossibility with no manual handling, provides a repeatable process for
ofswarfcontaminationfromthecasingmaterialduringcutting. establishing limits and trends.
7.3.4 Sectional Testing—Sections of the filter may also be
7.3 Debris Extraction Process—There are several methods
cut from the filter for extraction of debris. The assumption is
for extracting debris from filters. They range from manually
that the debris is representative for the entire filter and an
removing large particles from the filter to automated filter back
estimation of total debris is made.Any of the debris extraction
flushing.
techniques mentioned above can be used. See Practice D7898.
7.3.1 Manual—Manual debris removal from filters has been
practiced for decades. Different means for removing the debris 7.4 Media for Debris Deposition—Once the debris has been
range from manually extracting large debris from the filter to extracted from the filter, it must be captured on some media to
immersing the entire filter or sections of the filter in a solvent enable further analysis. Membrane patches are typically uti-
(such as polyol ester) compatible with the component oil lized. Membrane patches come in a variety of diameters (for
system, separating the debris removed from the solvent by example, 47 mm and 25 mm diameter), porosities (for
suction flask or simple gravity drain through cellulose media example, 20 µm to 100 µm) and materials (for example, nylon
such as a coffee filter, and then analyzing the debris by visual, and cellulose). The choice of membrane pore size is generally
microscopic, or elemental methods. While manual techniques a compromise between particle isolation and prevention of
can be subjective and prone to interpretation anomalies, they clogging by finer contaminants such as oil degradation prod-
ucts and soot; and compatibility with fluids in the filters and
those used for the extraction process.
FIG. 1 Filter Element with Removable Diagnostic Layer FIG. 2 Particles Count
...