ASTM D7624-10
(Test Method)Standard Test Method for Condition Monitoring of Nitration in In-Service Petroleum and Hydrocarbon-Based Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry
Standard Test Method for Condition Monitoring of Nitration in In-Service Petroleum and Hydrocarbon-Based Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry
SIGNIFICANCE AND USE
There is a wide variety of nitration compounds that may be produced and accumulate when oils react with gaseous nitrates formed during the engine combustion process. These nitration products may increase the viscosity, acidity and insolubles in the oil, which may lead to ring sticking and filter plugging. Monitoring of nitration products is therefore an important parameter in determining overall machinery health and should be considered in conjunction with data from other tests such as atomic emission (AE) and atomic absorption (AA) spectroscopy for wear metal analysis (Test Method D5185), physical property tests (Test Methods D445, D6304, and D2896), and other FT-IR oil analysis methods for oxidation (Test Method ), sulfate by-products (Test Method D7415), additive depletion (Test Method D7412), and breakdown products and external contaminants (Practice E2412), which also assess elements of the oil’s condition. (1-6)
SCOPE
1.1 This test method covers monitoring nitration in gasoline and natural gas engine oils as well as in other types of lubricants where nitration by-products may form due to the combustion process or other routes of formation of nitration compounds.
1.2 This test method uses FT-IR spectroscopy for monitoring build-up of nitration by-products in in-service petroleum and hydrocarbon-based lubricants as a result of normal machinery operation. Nitration levels in gasoline and natural gas engine oils rise as combustion by-products react with the oil as a result of exhaust gas recirculation or a blow-by. This test method is designed as a fast, simple spectroscopic check for monitoring of nitration in in-service petroleum and hydrocarbon-based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of nitration in the oil.
1.3 Acquisition of FT-IR spectral data for measuring nitration in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for nitration using both direct trend analysis and differential (spectral subtraction) trend analysis are presented.
1.4 This test method is based on trending of spectral changes associated with nitration in in-service petroleum and hydrocarbon-based lubricants. For direct trend analysis, values are recorded directly from absorption spectra and reported in units of 100*absorbance per 0.1 mm pathlength (or equivalently absorbance units per centimetre). For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the spectrum of the reference oil from that of the in-service oil) and reported in units of 100*absorbance per 0.1 mm pathlength (or equivalently absorbance units per centimetre). Warnings or alarm limits can be set on the basis of a fixed maximum value for a single measurement or, alternatively, can be based on a rate of change of the response measured. (1) In either case, such maintenance action limits should be determined through statistical analysis, history of the same or similar equipment, round robin tests or other methods in conjunction with the correlation of nitration changes to equipment performance.
Note 1—It is not the intent of this test method to establish or recommend normal, cautionary, warning or alert limits for any machinery. Such limits should be established in conjunction with advice and guidance from the machinery manufacturer and maintenance group.
1.5 This test method is for petroleum and hydrocarbon-based lubricants and is not applicable for ester-based oils, including polyol esters or phosphate esters.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6.1 Exception—The unit for wave numbers is cm-1.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is t...
General Information
Standards Content (Sample)
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Designation: D7624 − 10
Standard Test Method for
Condition Monitoring of Nitration in In-Service Petroleum
and Hydrocarbon-Based Lubricants by Trend Analysis
1
Using Fourier Transform Infrared (FT-IR) Spectrometry
This standard is issued under the fixed designation D7624; 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 lently absorbance units per centimetre). Warnings or alarm
limits can be set on the basis of a fixed maximum value for a
1.1 This test method covers monitoring nitration in gasoline
single measurement or, alternatively, can be based on a rate of
and natural gas engine oils as well as in other types of
2
change of the response measured. (1) In either case, such
lubricants where nitration by-products may form due to the
maintenance action limits should be determined through sta-
combustion process or other routes of formation of nitration
tistical analysis, history of the same or similar equipment,
compounds.
round robin tests or other methods in conjunction with the
1.2 This test method uses FT-IR spectroscopy for monitor-
correlation of nitration changes to equipment performance.
ing build-up of nitration by-products in in-service petroleum
NOTE 1—It is not the intent of this test method to establish or
and hydrocarbon-based lubricants as a result of normal ma-
recommend normal, cautionary, warning or alert limits for any machinery.
chinery operation. Nitration levels in gasoline and natural gas
Suchlimitsshouldbeestablishedinconjunctionwithadviceandguidance
engine oils rise as combustion by-products react with the oil as
from the machinery manufacturer and maintenance group.
a result of exhaust gas recirculation or a blow-by. This test
1.5 This test method is for petroleum and hydrocarbon-
method is designed as a fast, simple spectroscopic check for
based lubricants and is not applicable for ester-based oils,
monitoring of nitration in in-service petroleum and
including polyol esters or phosphate esters.
hydrocarbon-based lubricants with the objective of helping
1.6 The values stated in SI units are to be regarded as
diagnose the operational condition of the machine based on
standard. No other units of measurement are included in this
measuring the level of nitration in the oil.
standard.
1.3 Acquisition of FT-IR spectral data for measuring nitra-
-1
1.6.1 Exception—The unit for wave numbers is cm .
tion in in-service oil and lubricant samples is described in
1.7 This standard does not purport to address all of the
Practice D7418. In this test method, measurement and data
safety concerns, if any, associated with its use. It is the
interpretation parameters for nitration using both direct trend
responsibility of the user of this standard to establish appro-
analysis and differential (spectral subtraction) trend analysis
priate safety and health practices and determine the applica-
are presented.
bility of regulatory limitations prior to use.
1.4 This test method is based on trending of spectral
changes associated with nitration in in-service petroleum and
2. Referenced Documents
hydrocarbon-based lubricants. For direct trend analysis, values
3
2.1 ASTM Standards:
are recorded directly from absorption spectra and reported in
D445 Test Method for Kinematic Viscosity of Transparent
units of 100*absorbance per 0.1 mm pathlength (or equiva-
and Opaque Liquids (and Calculation of Dynamic Viscos-
lently absorbance units per centimetre). For differential trend
ity)
analysis, values are recorded from the differential spectra
D2896 Test Method for Base Number of Petroleum Products
(spectrum obtained by subtraction of the spectrum of the
by Potentiometric Perchloric Acid Titration
reference oil from that of the in-service oil) and reported in
D5185 Test Method for Multielement Determination of
units of 100*absorbance per 0.1 mm pathlength (or equiva-
Used and Unused Lubricating Oils and Base Oils by
1 2
This test method is under the jurisdiction of ASTM Committee D02 on The boldface numbers in parentheses refer to a list of references at the end of
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of this standard.
3
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 Aug. 1, 2010. Published September 2010. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7624–10. the ASTM website.
Copyright © ASTM
...
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