ASTM D7415-22

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: D7415 − 22
Standard Test Method for
Condition Monitoring of Sulfate By-Products in In-Service
Petroleum and Hydrocarbon Based Lubricants by Trend
Analysis Using Fourier Transform Infrared (FT-IR)
1
Spectrometry
This standard is issued under the fixed designation D7415; 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* for a single measurement or, alternatively, can be based on a
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rate of change of the response measured, see Ref (1).
1.1 This test method covers monitoring sulfate by-products
1.4.1 For direct trend analysis, values are recorded directly
in in-service petroleum and hydrocarbon based diesel crank-
fromabsorptionspectraandreportedinunitsofabsorbanceper
case engine and motor oils that have a sulfur content of greater
0.1 mm pathlength.
than 500 ppm. This test method should not be employed when
1.4.2 For differential trend analysis, values are recorded
low-sulfur fuels are used for combustion.
from the differential spectra (spectrum obtained by subtraction
of the absorption spectrum of the reference oil from that of the
1.2 This test method uses Fourier Transform Infrared (FT-
in-service oil) and reported in units of 100*absorbance per
IR) spectrometry for monitoring build-up of sulfate by-
0.1 mm pathlength (or equivalently absorbance units per cen-
products in in-service petroleum and hydrocarbon based lubri-
timetre).
cants as a result of normal machinery operation. Sulfate
1.4.3 In either case, maintenance action limits should be
by-products can result from the introduction of sulfur from
determined through statistical analysis, history of the same or
combustion or from the oxidation of sulfur-containing base oil
similar equipment, round robin tests, or other methods in
additives. This test method is designed as a fast, simple
conjunction with the correlation of sulfate by-product changes
spectroscopic check for monitoring of sulfate by-products in
to equipment performance.
in-service petroleum and hydrocarbon based lubricants with
the objective of helping diagnose the operational condition of
NOTE 1—It is not the intent of this test method to establish or
the machine based on measuring the level of sulfate by- recommendnormal,cautionary,warning,oralertlimitsforanymachinery.
Suchlimitsshouldbeestablishedinconjunctionwithadviceandguidance
products in the oil.
from the machinery manufacturer and maintenance group.
1.3 Acquisition of FT-IR spectral data for measuring sulfate
1.5 This test method is for petroleum and hydrocarbon
by-products in in-service oil and lubricant samples is described
based lubricants and is not applicable for ester based oils,
in Practice D7418. In this test method, measurement and data
including polyol esters or phosphate esters.
interpretation parameters for sulfate by-products using both
1.6 The values stated in SI units are to be regarded as
directtrendanalysisanddifferential(spectralsubtraction)trend
standard. No other units of measurement are included in this
analysis are presented.
standard.
-1
1.4 This test method is based on trending of spectral
1.6.1 Exception—The unit for wave numbers is cm .
changes associated with sulfate by-products of in-service
1.7 This standard does not purport to address all of the
petroleum and hydrocarbon based lubricants. Warnings or
safety concerns, if any, associated with its use. It is the
alarm limits can be set on the basis of a fixed minimum value
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1
1.8 This international standard was developed in accor-
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
dance with internationally recognized principles on standard-
Subcommittee D02.96.03 on FTIR Testing Practices and Techniques Related to
ization established in the Decision on Principles for the
In-Service Lubricants.
Current edition approved Oct. 1, 2022. Published October 2022. Originally
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approved in 2009. Last previous edition approved in 2021 as D7415 – 21. DOI: The boldface numbers in parentheses refer to a list of references at the end of
10.1520/D7415-22. this standard.
*A Summary of Changes section appears at the end of this standard
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