ASTM D7844-12

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Designation: D7844 − 12
Standard Test Method for
Condition Monitoring of Soot in In-Service Lubricants by
Trend Analysis using Fourier Transform Infrared (FT-IR)
Spectrometry
This standard is issued under the fixed designation D7844; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope be based on a rate of change of the response measured (1). In
either case, such maintenance action limits should be deter-
1.1 This test method pertains to field-based monitoring soot
mined through statistical analysis, history of the same or
in diesel crankcase engine oils as well as in other types of
similar equipment, round robin tests or other methods in
engine oils where soot may contaminate the lubricant as a
conjunction with the correlation of soot levels to equipment
resultofablow-byduetoincompletecombustionofin-service
performance.
fuels.
NOTE 1—It is not the intent of this test method to establish or
recommendnormal,cautionary,warningoralertlimitsforanymachinery.
1.2 This test method uses FT-IR spectroscopy for monitor-
Suchlimitsshouldbeestablishedinconjunctionwithadviceandguidance
ing of soot build-up in in-service lubricants as a result of
from the machinery manufacturer and maintenance group.
normal machinery operation. Soot levels in engine oils rise as
1.5 Thistestmethodisprimarilyforpetroleum/hydrocarbon
soot particles contaminate the oil as a result of exhaust gas
based lubricants but is also applicable for ester based oils,
recirculation or a blow-by. This test method is designed as a
including polyol esters or phosphate esters.
fast, simple spectroscopic check for monitoring of soot in
1.6 This method is intended as a field test only, and should
in-servicelubricantswiththeobjectiveofhelpingdiagnosethe
be treated as such. Critical applications should use laboratory
operational condition of the machine based on measuring the
based methods, such as Thermal Gravimetric (TGA) analysis
level of soot in the oil.
described in Standard Method D5967, Annex A4.
1.3 AcquisitionofFT-IRspectraldataformeasuringsootin
1.7 This standard does not purport to address all of the
in-service oil and lubricant samples is described in Standard
safety concerns, if any, associated with its use. It is the
Practice D7418. In this test method, measurement and data
responsibility of the user of this standard to establish appro-
interpretation parameters for soot using both direct trend
priate safety and health practices and determine the applica-
analysis and differential (spectral subtraction) trend analysis
bility of regulatory limitations prior to use.
are presented.
2. Referenced Documents
1.4 This test method is based on trending of spectral
changesassociatedwithsootinin-servicelubricants.Fordirect
2.1 ASTM Standards:
trend analysis, values are recorded directly from absorbance
D445Test Method for Kinematic Viscosity of Transparent
spectra and reported in units of 100*absorbance per 0.1 mm
and Opaque Liquids (and Calculation of DynamicViscos-
pathlength. For differential trend analysis, values are recorded
ity)
from the differential spectra (spectrum obtained by subtraction
D2896TestMethodforBaseNumberofPetroleumProducts
of the spectrum of the reference oil from that of the in-service
by Potentiometric Perchloric Acid Titration
oil) and reported in units of 100*absorbance per 0.1 mm
D5185Test Method for Multielement Determination of
pathlength (or equivalently absorbance units per centimeter).
Used and Unused Lubricating Oils and Base Oils by
Warnings or alarm limits can be set on the basis of a fixed
Inductively Coupled Plasma Atomic Emission Spectrom-
maximumvalueforasinglemeasurementor,alternatively,can
etry (ICP-AES)
1 2
This test method is under the jurisdiction of ASTM Committee D02 on Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of this standard.
Subcommittee D02.96.03 on FTIR Testing Practices and Techniques Related to For referenced ASTM standards, visit the ASTM website, www.astm.org, or
In-Service Lubricants. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Dec. 1, 2012. Published January 2013. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7844-12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7844 − 12
D5967Test Method for Evaluation of Diesel Engine Oils in for diesel engines, although it may also be an indicator of
T-8 Diesel Engine carburetor or injector problems in other fuel systems. Moni-
D6304Test Method for Determination of Water in Petro- toring of soot is therefore an important parameter in determin-
leum Products, Lubricating Oils, and Additives by Cou- ing overall machinery health and should be considered in
lometric Karl Fischer Titration conjunctionwithdatafromothertestssuchasatomicemission
D7412Test Method for Condition Monitoring of Phosphate (AE) and atomic absorption (AA) spectroscopy for wear metal
Antiwear Additives in In-Service Petroleum and Hydro- analysis (Test Method D5185), physical property tests (Test
carbonBasedLubricantsbyTrendAnalysisUsingFourier Methods D445, D6304 and D2896), and other FT-IR oil
Transform Infrared (FT-IR) Spectrometry analysis methods for oxidation (Test Method D7414), sulfate
D7414Test Method for Condition Monitoring of Oxidation by-products (Test Method D7415), nitration (Test Method
in In-Service Petroleum and Hydrocarbon Based Lubri- D7624), additive depletion (Test Method D7412), and break-
cantsbyTrendAnalysisUsingFourierTransformInfrared down products and external contaminants (Practice E2412),
(FT-IR) Spectrometry which also assess elements of the oil’s condition (1-6).
D7415Test Method for Condition Monitoring of Sulfate
6. Interferences
By-Products in In-Service Petroleum and Hydrocarbon
Based Lubricants byTrendAnalysis Using FourierTrans-
6.1 High levels of water (>5%) will interfere with the soot
form Infrared (FT-IR) Spectrometry
measurement in internal combustion engine crankcases. Other
D7418Practice for Set-Up and Operation of Fourier Trans-
interferencesincludehighlevelsofsludgeorinsolubles.These
form Infrared (FT-IR) Spectrometers for In-Service Oil
interferences will increase the measured soot values.
Condition Monitoring
7. Apparatus
D7624TestMethodforConditionMonitoringofNitrationin
In-Service Petroleum and Hydrocarbon-Based Lubricants
7.1 Fourier Transform Infrared Spectrometer, equipped
by Trend Analysis Using Fourier Transform Infrared
with sample cell, filter and pumping system (optional) as
(FT-IR) Spectrometry
specified in Standard Practice D7418.
E131Terminology Relating to Molecular Spectroscopy
7.2 FT-IR Spectral Acquisition Parameters—Set FT-IR
E2412Practice for Condition Monitoring of In-Service Lu-
spectral acquisition parameters according to instructions in
bricants by Trend Analysis Using Fourier Transform
Standard Practice D7418.
Infrared (FT-IR) Spectrometry
8. Sampling
3. Terminology
8.1 Obtain a sample of the in-service oil and the reference
3.1 Definitions—Fordefinitionsoftermsrelatingtoinfrared
oil according to the protocol described in Standard Practice
spectroscopy used in this test method, refer to Terminology
D7418.
E131.
3.2 Definitions—Fordefinitionoftermsrelatedtoin-service
9. Preparation and Maintenance of Apparatus
oil condition monitoring, refer to Practice D7418.
9.1 Rinse, flush and clean the sample cell, lines and inlet
3.3 Definitions of Terms Specific to This Standard:
filter according to instructions in Standard Practice D7418.
3.3.1 machinery health, n—a qualitative expression of the
9.2 MonitorcellpathlengthasspecifiedinStandardPractice
operational status of a machine sub-component, component or
D7418.
entire machine, used to communicate maintenance and opera-
tional recommendations or requirements in order to continue
10. Procedure and Calculation
operation, schedule maintenance or take immediate mainte-
10.1 Collect a background spectrum according to the pro-
nance action.
cedure
...