D02.96.03 - FTIR Testing Practices and Techniques Related to In-Service Lubricants

SIGNIFICANCE AND USE
5.1 Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health. Atomic emission (AE) and atomic absorption (AA) spectroscopy are often employed for wear metal analysis (for example, Test Method D5185). A number of physical property tests complement wear metal analysis and are used to provide information on lubricant condition (for example, Test Methods D445, D2896, and D6304). Molecular analysis of lubricants and hydraulic fluids by FT-IR spectroscopy produces direct information on molecular species of interest, including additives, fluid breakdown products and external contaminants, and thus complements wear metal and other analyses used in a condition monitoring program (1, 2-6).
SCOPE
1.1 This practice covers the use of FT-IR in monitoring additive depletion, contaminant buildup and base stock degradation in machinery lubricants, hydraulic fluids and other fluids used in normal machinery operation. Contaminants monitored include water, soot, ethylene glycol, fuels and incorrect oil. Oxidation, nitration and sulfonation of base stocks are monitored as evidence of degradation. The objective of this monitoring activity is to diagnose the operational condition of the machine based on fault conditions observed in the oil. Measurement and data interpretation parameters are presented to allow operators of different FT-IR spectrometers to compare results by employing the same techniques.  
1.2 This practice is based on trending and distribution response analysis from mid-infrared absorption measurements. While calibration to generate physical concentration units may be possible, it is unnecessary or impractical in many cases. Warning or alarm limits (the point where maintenance action on a machine being monitored is recommended or required) can be determined through statistical analysis, history of the same or similar equipment, round robin tests or other methods in conjunction with correlation to equipment performance. These warning or alarm limits can be a fixed maximum or minimum value for comparison to a single measurement or can also be based on a rate of change of the response measured (1) .2 This practice describes distributions but does not preclude using rate-of-change warnings and alarms.
Note 1: It is not the intent of this practice 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.  
1.3 Spectra and distribution profiles presented herein are for illustrative purposes only and are not to be construed as representing or establishing lubricant or machinery guidelines.  
1.4 This practice is designed as a fast, simple spectroscopic check for condition monitoring of in-service lubricants and can be used to assist in the determination of general machinery health through measurement of properties observable in the mid-infrared spectrum such as water, oil oxidation, and others as noted in 1.1. The infrared data generated by this practice is typically used in conjunction with other testing methods. For example, infrared spectroscopy cannot determine wear metal levels or any other type of elemental analysis. The practice as presented is not intended for the prediction of lubricant physical properties (for example, viscosity, total base number, total acid number, etc.). This practice is designed for monitoring in-service lubricants and can aid in the determination of general machinery health and is not designed for the analysis of lubricant composition, lubricant performance or additive package formulations.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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 t...

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (4-7). Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 This test method provides a simple field-based technique for condition monitoring of soot in in-service lubricants associated with combustion engines, machinery, and equipment used in industry and by the military. Critical applications should use laboratory-based test methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4. Infrared spectroscopy is a well-established laboratory method for evaluating soot levels in lubricants. This test method can be used to monitor soot build-up in lubricants and can indicate whether soot has accumulated to an extent that could significantly degrade the performance of the oil. High soot content can compromise lubricant performance and cause filter and oil passage blockage. Soot concentration should be considered in conjunction with data from other condition monitoring tests as described in Practice E2412 to determine whether the oil should be replaced to minimize machinery wear or failure, or both.
SCOPE
1.1 This test method pertains to field-based monitoring of soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of fuels. It is applicable to oils having soot levels of up to 12 % by mass.  
1.2 This test method uses filter-based infrared technology for monitoring of soot build-up in in-service petroleum and hydrocarbon-based lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate the oil as a result of exhaust gas recirculation from blow-by. This test method is designed as a fast, simple, and field-capable spectroscopic check for soot in in-service hydrocarbon-based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 This test method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4.  
1.4 Acquisition of spectral data for measuring soot in in-service oil and lubricant samples with the use of a fixed-filter IR instrument is described in this test method. Calibration against prepared soot standards is also described.
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 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
5.1 The PAI is representative of the quantity of all the compounds containing a carbonyl function that have formed by the oxidation of the lubricant (aldehydes, ketones, carboxylic acids, esters, anhydrides, etc.). The PAI gives representative information on the chemical degradation of the lubricant which has been caused by oxidation.  
5.2 This test method was developed for transmission oils and is used in the CEC L-48-A-00 test (Oxidation Stability of Lubricating Oils Used in Automotive Transmissions by Artificial Aging) as a parameter for the end of test evaluation.
SCOPE
1.1 This test method covers the determination of the oxidation of used lubricants by FT-IR (Fourier Transform Infrared Spectroscopy). It measures the concentration change of constituents containing a carbonyl function that have formed during the oxidation of the lubricant.  
1.2 This test method may be used to indicate relative changes that occur in an oil under oxidizing conditions. The test method is not intended to measure an absolute oxidation property that can be used to predict performance of an oil in service.  
1.3 This test method was developed for transmission oils which have been degraded either in service, or in a laboratory test, for example a bulk oxidation test. It may be used for other in-service oils, but the stated precision may not apply.  
1.4 The results of this test method may be affected by the presence of other components with an absorbance band in the zone of 1600 cm-1 to 1800 cm-1. Low PAI values may be difficult to determine in those cases. Section 6 describes these possible interferences in more detail.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
5.1 Antiwear additives are commonly used in petroleum and hydrocarbon based lubricants to prevent machinery wear by forming a chemical barrier activated by frictional heat. Antiwear additives that are phosphate based can be measured by FT-IR spectroscopy using the phosphate absorption band. Initially, phosphate antiwear additives will decompose and form a protective film by binding to metal surfaces and through oxidative mechanisms, and so a decrease in the level of phosphate antiwear additive relative to that in the new oil is expected during normal machinery operation. Subsequently, significant depletion of phosphate antiwear additives due to oxidation or hydrolysis can occur when the lubricant is subjected to high temperatures and high levels of moisture. This usually occurs prior to the point where the oxidation of the lubricant begins to accelerate, making trending of phosphate antiwear additives a useful indicator of the lubricant’s remaining in-service life. Monitoring of phosphate antiwear additive depletion 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 and D2896) and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), and nitration (Test Method D7624), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants such as various types of engine oils, hydraulic oils, and other lubricants that are formulated for protection against wear. Typical phosphate antiwear additives include zinc dialkyldithiophosphates, trialkyl phosphates, and triaryl phosphates.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring of phosphate antiwear additive depletion in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Monitoring the depletion of phosphate antiwear additives in in-service lubricants can indicate unusual wear or severe operating conditions of the machine. This test method is designed as a fast, simple spectroscopic check for monitoring of phosphate antiwear additives 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 phosphate antiwear additives in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring phosphate antiwear additives in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for phosphate antiwear additives 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 phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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 centimeter).  
1.4.3 In either case, maintenance action limits should be determined through statistical analysis, history of the same or simila...

SIGNIFICANCE AND USE
5.1 A large number of compounds, such as aldehydes, ketones, esters, and carboxylic acids, are produced when oils react with atmospheric oxygen. Oxidation is measured using a common FT-IR spectral feature between 1800 cm–1 and 1670 cm–1 caused by the absorption of the carbonyl group present in most oxidation compounds. These oxidation products may lead to increased viscosity (causing oil thickening problems), acidity (causing acidic corrosion), and formation of sludge and varnish (leading to filter plugging, fouling of critical oil clearances and valve friction). Monitoring of oxidation 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) and physical property tests (Test Methods D445), base reserve (Test Method D2896 and D4739), acid number tests (Test Methods D664 and D974) and other FT-IR oil analysis methods for nitration (Test Method D7624), sulfate by-products (Test Method D7415), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to oxidation.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of oxidation products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants react with oxygen in the air to form a number of different chemical species, including aldehydes, ketones, esters, and carboxylic acids. This test method is designed as a fast, simple spectroscopic check for monitoring of oxidation 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 oxidation in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring oxidation in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for oxidation 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 oxidation of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 oxidation 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 es...

SIGNIFICANCE AND USE
5.1 An increase in sulfate material can be an indicator of oil degradation caused by oxidation of sulfur in the oil and sulfur in fuel. It can also indicate the breakdown or oxidation of some key additives in the oil such as antiwear and extreme pressure additives as well as blow-by concerns. As oxidized sulfur from blow-by enters the lubricant, it will consume the overbase additive to generate sulfate by-products. Monitoring of sulfate by-products is therefore an important parameter in determining overall machinery health and in determining additive depletion 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 and D2896), base number tests (Test Methods D974 and D4739), and other FT-IR oil analysis methods for nitration (Test Method D7624), oxidation (Test Method D7414), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring sulfate by-products in in-service petroleum and hydrocarbon based diesel crankcase engine and motor oils that have a sulfur content of greater than 500 ppm. This test method should not be employed when low-sulfur fuels are used for combustion.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Sulfate by-products can result from the introduction of sulfur from combustion or from the oxidation of sulfur-containing base oil additives. This test method is designed as a fast, simple spectroscopic check for monitoring of sulfate by-products 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 sulfate by-products in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring sulfate by-products in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for sulfate by-products 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 sulfate by-products of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 sulfate by-product 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...

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity. Monitoring of soot 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 and D2896), and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition (1-6).
SCOPE
1.1 This test method pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels to equipment performance.  
1.4.1 Interpretation of soot values reported as a percentage is more widely understood within the industry. As an alternate reporting option, an equation to convert the soot absorbance value generated from Procedure A (direct trend) analysis to percent is provided. This equation is based on the Beer-Lambert law which states that concentration is directly proportional to absorbance.
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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric (TGA) analysis described in Standard Method D5967, Annex A4.  
1.7 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 th...

SIGNIFICANCE AND USE
5.1 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 and D2896), and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), and additive depletion (Test Method D7412), 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).2 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 the responsibility of the user of this standard to estab...

SIGNIFICANCE AND USE
5.1 This test method provides a means for obtaining useful in-service fluid analysis properties in the field. It is not to be confused with laboratory or portable FTIR devices which provide measurements per the existing Test Methods listed in 4.1.1.1. Each of these monitored properties has been shown over time to indicate either contamination in the fluid system or a particular breakdown modality of the fluid, which is critical information to assess the health of the fluid as well as the machinery. By utilizing the field device, it is possible for those operating machinery, in locations and situations where it is not practical to gather a sample for the laboratory, to obtain quality in-service fluid analysis. This may be due to the need to have an analysis done in real-time, on-the-spot to maximize the operational hours of equipment, or to have the analysis performed at a location where no laboratory analysis is available.
SCOPE
1.1 This test method describes the use of a grating spectrometer to analyze properties of an in-service fluid sample which are indicative of the status of that fluid and related machinery.  
1.2 This test method provides a means for the assessment of in-service fluid properties using infrared spectroscopy. It describes a methodology for sampling, performing analysis, and providing key in-service fluid properties with a self-contained unit that is meant for field use. It provides analysis of in-service fluids at any stage of their useful life, including newly utilized fluid.  
1.3 In particular, these key in-service fluid properties include oxidation, nitration, sulfation, soot, and antiwear additives. They are applicable for hydrocarbon type (API Group I-IV) fluids from machinery lubricants, including reciprocating engine oils, turbine oils, hydraulic oils, and gear oils.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4.1 Exception—The unit for wavenumbers is in cm-1.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health. Atomic emission (AE) and atomic absorption (AA) spectroscopy are often employed for wear metal analysis (for example, Test Method D5185). A number of physical property tests complement wear metal analysis and are used to provide information on lubricant condition (for example, Test Methods D445, D2896, and D6304). Molecular analysis of lubricants and hydraulic fluids by FT-IR spectroscopy produces direct information on molecular species of interest, including additives, fluid breakdown products and external contaminants, and thus complements wear metal and other analyses used in a condition monitoring program (1, 2-6).
SCOPE
1.1 This practice covers the use of FT-IR in monitoring additive depletion, contaminant buildup and base stock degradation in machinery lubricants, hydraulic fluids and other fluids used in normal machinery operation. Contaminants monitored include water, soot, ethylene glycol, fuels and incorrect oil. Oxidation, nitration and sulfonation of base stocks are monitored as evidence of degradation. The objective of this monitoring activity is to diagnose the operational condition of the machine based on fault conditions observed in the oil. Measurement and data interpretation parameters are presented to allow operators of different FT-IR spectrometers to compare results by employing the same techniques.  
1.2 This practice is based on trending and distribution response analysis from mid-infrared absorption measurements. While calibration to generate physical concentration units may be possible, it is unnecessary or impractical in many cases. Warning or alarm limits (the point where maintenance action on a machine being monitored is recommended or required) can be determined through statistical analysis, history of the same or similar equipment, round robin tests or other methods in conjunction with correlation to equipment performance. These warning or alarm limits can be a fixed maximum or minimum value for comparison to a single measurement or can also be based on a rate of change of the response measured (1) .2 This practice describes distributions but does not preclude using rate-of-change warnings and alarms.
Note 1: It is not the intent of this practice 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.  
1.3 Spectra and distribution profiles presented herein are for illustrative purposes only and are not to be construed as representing or establishing lubricant or machinery guidelines.  
1.4 This practice is designed as a fast, simple spectroscopic check for condition monitoring of in-service lubricants and can be used to assist in the determination of general machinery health through measurement of properties observable in the mid-infrared spectrum such as water, oil oxidation, and others as noted in 1.1. The infrared data generated by this practice is typically used in conjunction with other testing methods. For example, infrared spectroscopy cannot determine wear metal levels or any other type of elemental analysis. The practice as presented is not intended for the prediction of lubricant physical properties (for example, viscosity, total base number, total acid number, etc.). This practice is designed for monitoring in-service lubricants and can aid in the determination of general machinery health and is not designed for the analysis of lubricant composition, lubricant performance or additive package formulations.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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 t...

SIGNIFICANCE AND USE
5.1 The PAI is representative of the quantity of all the compounds containing a carbonyl function that have formed by the oxidation of the lubricant (aldehydes, ketones, carboxylic acids, esters, anhydrides, etc.). The PAI gives representative information on the chemical degradation of the lubricant which has been caused by oxidation.  
5.2 This test method was developed for transmission oils and is used in the CEC L-48-A-00 test (Oxidation Stability of Lubricating Oils Used in Automotive Transmissions by Artificial Aging) as a parameter for the end of test evaluation.
SCOPE
1.1 This test method covers the determination of the oxidation of used lubricants by FT-IR (Fourier Transform Infrared Spectroscopy). It measures the concentration change of constituents containing a carbonyl function that have formed during the oxidation of the lubricant.  
1.2 This test method may be used to indicate relative changes that occur in an oil under oxidizing conditions. The test method is not intended to measure an absolute oxidation property that can be used to predict performance of an oil in service.  
1.3 This test method was developed for transmission oils which have been degraded either in service, or in a laboratory test, for example a bulk oxidation test. It may be used for other in-service oils, but the stated precision may not apply.  
1.4 The results of this test method may be affected by the presence of other components with an absorbance band in the zone of 1600 cm-1 to 1800 cm-1. Low PAI values may be difficult to determine in those cases. Section 6 describes these possible interferences in more detail.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (4-7). Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity. Monitoring of soot 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 and D2896), and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition (1-6).
SCOPE
1.1 This test method pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels to equipment performance.  
1.4.1 Interpretation of soot values reported as a percentage is more widely understood within the industry. As an alternate reporting option, an equation to convert the soot absorbance value generated from Procedure A (direct trend) analysis to percent is provided. This equation is based on the Beer-Lambert law which states that concentration is directly proportional to absorbance.
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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric (TGA) analysis described in Standard Method D5967, Annex A4.  
1.7 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 th...

SIGNIFICANCE AND USE
5.1 Antiwear additives are commonly used in petroleum and hydrocarbon based lubricants to prevent machinery wear by forming a chemical barrier activated by frictional heat. Antiwear additives that are phosphate based can be measured by FT-IR spectroscopy using the phosphate absorption band. Initially, phosphate antiwear additives will decompose and form a protective film by binding to metal surfaces and through oxidative mechanisms, and so a decrease in the level of phosphate antiwear additive relative to that in the new oil is expected during normal machinery operation. Subsequently, significant depletion of phosphate antiwear additives due to oxidation or hydrolysis can occur when the lubricant is subjected to high temperatures and high levels of moisture. This usually occurs prior to the point where the oxidation of the lubricant begins to accelerate, making trending of phosphate antiwear additives a useful indicator of the lubricant’s remaining in-service life. Monitoring of phosphate antiwear additive depletion 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 and D2896) and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), and nitration (Test Method D7624), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants such as various types of engine oils, hydraulic oils, and other lubricants that are formulated for protection against wear. Typical phosphate antiwear additives include zinc dialkyldithiophosphates, trialkyl phosphates, and triaryl phosphates.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring of phosphate antiwear additive depletion in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Monitoring the depletion of phosphate antiwear additives in in-service lubricants can indicate unusual wear or severe operating conditions of the machine. This test method is designed as a fast, simple spectroscopic check for monitoring of phosphate antiwear additives 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 phosphate antiwear additives in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring phosphate antiwear additives in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for phosphate antiwear additives 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 phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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 centimeter).  
1.4.3 In either case, maintenance action limits should be determined through statistical analysis, history of the same or simila...

SIGNIFICANCE AND USE
5.1 A large number of compounds, such as aldehydes, ketones, esters, and carboxylic acids, are produced when oils react with atmospheric oxygen. Oxidation is measured using a common FT-IR spectral feature between 1800 cm–1 and 1670 cm–1 caused by the absorption of the carbonyl group present in most oxidation compounds. These oxidation products may lead to increased viscosity (causing oil thickening problems), acidity (causing acidic corrosion), and formation of sludge and varnish (leading to filter plugging, fouling of critical oil clearances and valve friction). Monitoring of oxidation 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) and physical property tests (Test Methods D445), base reserve (Test Method D2896 and D4739), acid number tests (Test Methods D664 and D974) and other FT-IR oil analysis methods for nitration (Test Method D7624), sulfate by-products (Test Method D7415), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to oxidation.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of oxidation products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants react with oxygen in the air to form a number of different chemical species, including aldehydes, ketones, esters, and carboxylic acids. This test method is designed as a fast, simple spectroscopic check for monitoring of oxidation 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 oxidation in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring oxidation in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for oxidation 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 oxidation of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 oxidation 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 es...

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (4-7). Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 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 and D2896), and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), and additive depletion (Test Method D7412), 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).2 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 the responsibility of the user of this standard to estab...

SIGNIFICANCE AND USE
5.1 An increase in sulfate material can be an indicator of oil degradation caused by oxidation of sulfur in the oil and sulfur in fuel. It can also indicate the breakdown or oxidation of some key additives in the oil such as antiwear and extreme pressure additives as well as blow-by concerns. As oxidized sulfur from blow-by enters the lubricant, it will consume the overbase additive to generate sulfate by-products. Monitoring of sulfate by-products is therefore an important parameter in determining overall machinery health and in determining additive depletion 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 and D2896), base number tests (Test Methods D974 and D4739), and other FT-IR oil analysis methods for nitration (Test Method D7624), oxidation (Test Method D7414), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring sulfate by-products in in-service petroleum and hydrocarbon based diesel crankcase engine and motor oils that have a sulfur content of greater than 500 ppm. This test method should not be employed when low-sulfur fuels are used for combustion.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Sulfate by-products can result from the introduction of sulfur from combustion or from the oxidation of sulfur-containing base oil additives. This test method is designed as a fast, simple spectroscopic check for monitoring of sulfate by-products 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 sulfate by-products in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring sulfate by-products in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for sulfate by-products 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 sulfate by-products of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 sulfate by-product 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...

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity. Monitoring of soot 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 and D2896), and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), and additive depletion (Test Method D7412), which also assess elements of the oil’s condition (1-6).
SCOPE
1.1 This test method pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels to equipment performance.  
1.4.1 Interpretation of soot values reported as a percentage is more widely understood within the industry. As an alternate reporting option, an equation to convert the soot absorbance value generated from Procedure A (direct trend) analysis to percent is provided. This equation is based on the Beer-Lambert law which states that concentration is directly proportional to absorbance.
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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric (TGA) analysis described in Standard Method D5967, Annex A4.  
1.7 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 th...

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (4-7), as described in Practice E2412. Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity, which is usually a consideration for diesel engines, although it may also be an indicator of carburetor or injector problems in other fuel systems. Monitoring of soot 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 D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), 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 pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels to equipment performance.  
1.4.1 Interpretation of soot values reported as a percentage is more widely understood within the industry. As an alternate reporting option, an equation to convert the soot absorbance value generated from Procedure A (direct trend) analysis to percent is provided. This equation is based on the Beer-Lambert law which states that concentration is directly proportional to absorbance.
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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravime...

SIGNIFICANCE AND USE
5.1 The PAI is representative of the quantity of all the compounds containing a carbonyl function that have formed by the oxidation of the lubricant (aldehydes, ketones, carboxylic acids, esters, anhydrides, etc.). The PAI gives representative information on the chemical degradation of the lubricant which has been caused by oxidation.  
5.2 This test method was developed for transmission oils and is used in the CEC L-48-A-00 test (Oxidation Stability of Lubricating Oils Used in Automotive Transmissions by Artificial Aging) as a parameter for the end of test evaluation.
SCOPE
1.1 This test method covers the determination of the oxidation of used lubricants by FT-IR (Fourier Transform Infrared Spectroscopy). It measures the concentration change of constituents containing a carbonyl function that have formed during the oxidation of the lubricant.  
1.2 This test method may be used to indicate relative changes that occur in an oil under oxidizing conditions. The test method is not intended to measure an absolute oxidation property that can be used to predict performance of an oil in service.  
1.3 This test method was developed for transmission oils which have been degraded either in service, or in a laboratory test, for example a bulk oxidation test. It may be used for other in-service oils, but the stated precision may not apply.  
1.4 The results of this test method may be affected by the presence of other components with an absorbance band in the zone of 1600 cm-1 to 1800 cm-1. Low PAI values may be difficult to determine in those cases. Section 6 describes these possible interferences in more detail.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (4-7), as described in Practice E2412. Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

SIGNIFICANCE AND USE
5.1 The PAI is representative of the quantity of all the compounds containing a carbonyl function that have formed by the oxidation of the lubricant (aldehydes, ketones, carboxylic acids, esters, anhydrides, etc.). The PAI gives representative information on the chemical degradation of the lubricant which has been caused by oxidation.  
5.2 This test method was developed for transmission oils and is used in the CEC L-48-A-00 test (Oxidation Stability of Lubricating Oils Used in Automotive Transmissions by Artificial Aging) as a parameter for the end of test evaluation.
SCOPE
1.1 This test method covers the determination of the oxidation of used lubricants by FT-IR (Fourier Transform Infrared Spectroscopy). It measures the concentration change of constituents containing a carbonyl function that have formed during the oxidation of the lubricant.  
1.2 This test method may be used to indicate relative changes that occur in an oil under oxidizing conditions. The test method is not intended to measure an absolute oxidation property that can be used to predict performance of an oil in service.  
1.3 This test method was developed for transmission oils which have been degraded either in service, or in a laboratory test, for example a bulk oxidation test. It may be used for other in-service oils, but the stated precision may not apply.  
1.4 The results of this test method may be affected by the presence of other components with an absorbance band in the zone of 1600 cm-1 to 1800 cm-1. Low PAI values may be difficult to determine in those cases. Section 6 describes these possible interferences in more detail.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
5.1 This test method provides a simple field-based technique for condition monitoring of soot in in-service lubricants associated with combustion engines, machinery, and equipment used in industry and by the military. Critical applications should use laboratory-based test methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4. Infrared spectroscopy is a well-established laboratory method for evaluating soot levels in lubricants. This test method can be used to monitor soot build-up in lubricants and can indicate whether soot has accumulated to an extent that could significantly degrade the performance of the oil. High soot content can compromise lubricant performance and cause filter and oil passage blockage. Soot concentration should be considered in conjunction with data from other condition monitoring tests as described in Practice E2412 to determine whether the oil should be replaced to minimize machinery wear or failure, or both.
SCOPE
1.1 This test method pertains to field-based monitoring of soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of fuels. It is applicable to oils having soot levels of up to 12 % by mass.  
1.2 This test method uses filter-based infrared technology for monitoring of soot build-up in in-service petroleum and hydrocarbon-based lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate the oil as a result of exhaust gas recirculation from blow-by. This test method is designed as a fast, simple, and field-capable spectroscopic check for soot in in-service hydrocarbon-based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 This test method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4.  
1.4 Acquisition of spectral data for measuring soot in in-service oil and lubricant samples with the use of a fixed-filter IR instrument is described in this test method. Calibration against prepared soot standards is also described.
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 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

SIGNIFICANCE AND USE
5.1 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 D7414), 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)2 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 ...

SIGNIFICANCE AND USE
5.1 Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health. Atomic emission (AE) and atomic absorption (AA) spectroscopy are often employed for wear metal analysis (for example, Test Method D5185). A number of physical property tests complement wear metal analysis and are used to provide information on lubricant condition (for example, Test Methods D445, D2896, and D6304). Molecular analysis of lubricants and hydraulic fluids by FT-IR spectroscopy produces direct information on molecular species of interest, including additives, fluid breakdown products and external contaminants, and thus complements wear metal and other analyses used in a condition monitoring program (1,3-2).
SCOPE
1.1 This practice covers the use of FT-IR in monitoring additive depletion, contaminant buildup and base stock degradation in machinery lubricants, hydraulic fluids and other fluids used in normal machinery operation. Contaminants monitored include water, soot, ethylene glycol, fuels and incorrect oil. Oxidation, nitration and sulfonation of base stocks are monitored as evidence of degradation. The objective of this monitoring activity is to diagnose the operational condition of the machine based on fault conditions observed in the oil. Measurement and data interpretation parameters are presented to allow operators of different FT-IR spectrometers to compare results by employing the same techniques.  
1.2 This practice is based on trending and distribution response analysis from mid-infrared absorption measurements. While calibration to generate physical concentration units may be possible, it is unnecessary or impractical in many cases. Warning or alarm limits (the point where maintenance action on a machine being monitored is recommended or required) can be determined through statistical analysis, history of the same or similar equipment, round robin tests or other methods in conjunction with correlation to equipment performance. These warning or alarm limits can be a fixed maximum or minimum value for comparison to a single measurement or can also be based on a rate of change of the response measured (1) .2 This practice describes distributions but does not preclude using rate-of-change warnings and alarms.
Note 1: It is not the intent of this practice 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.  
1.3 Spectra and distribution profiles presented herein are for illustrative purposes only and are not to be construed as representing or establishing lubricant or machinery guidelines.  
1.4 This practice is designed as a fast, simple spectroscopic check for condition monitoring of in-service lubricants and can be used to assist in the determination of general machinery health through measurement of properties observable in the mid-infrared spectrum such as water, oil oxidation, and others as noted in 1.1. The infrared data generated by this practice is typically used in conjunction with other testing methods. For example, infrared spectroscopy cannot determine wear metal levels or any other type of elemental analysis. The practice as presented is not intended for the prediction of lubricant physical properties (for example, viscosity, total base number, total acid number, etc.). This practice is designed for monitoring in-service lubricants and can aid in the determination of general machinery health and is not designed for the analysis of lubricant composition, lubricant performance or additive package formulations.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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 th...

SIGNIFICANCE AND USE
5.1 Antiwear additives are commonly used in petroleum and hydrocarbon based lubricants to prevent machinery wear by forming a chemical barrier activated by frictional heat. Antiwear additives that are phosphate based can be measured by FT-IR spectroscopy using the phosphate absorption band. Initially, phosphate antiwear additives will decompose and form a protective film by binding to metal surfaces and through oxidative mechanisms, and so a decrease in the level of phosphate antiwear additive relative to that in the new oil is expected during normal machinery operation. Subsequently, significant depletion of phosphate antiwear additives due to oxidation or hydrolysis can occur when the lubricant is subjected to high temperatures and high levels of moisture. This usually occurs prior to the point where the oxidation of the lubricant begins to accelerate, making trending of phosphate antiwear additives a useful indicator of the lubricant’s remaining in-service life. Monitoring of phosphate antiwear additive depletion 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, D2896, and D6304) and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), nitration, breakdown products and external contaminants (Practice E2412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants such as various types of engine oils, hydraulic oils, and other lubricants that are formulated for protection against wear. Typical phosphate antiwear additives include zinc dialkyldithiophosphates, trialkyl phosphates, and triaryl phosphates.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring of phosphate antiwear additive depletion in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Monitoring the depletion of phosphate antiwear additives in in-service lubricants can indicate unusual wear or severe operating conditions of the machine. This test method is designed as a fast, simple spectroscopic check for monitoring of phosphate antiwear additives 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 phosphate antiwear additives in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring phosphate antiwear additives in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for phosphate antiwear additives 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 phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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 centimeter).  
1.4.3 In either case, maintenance action limits should be determined through stat...

SIGNIFICANCE AND USE
5.1 A large number of compounds, such as aldehydes, ketones, esters, and carboxylic acids, are produced when oils react with atmospheric oxygen. Oxidation is measured using a common FT-IR spectral feature between 1800 and 1670 cm–1 caused by the absorption of the carbonyl group present in most oxidation compounds. These oxidation products may lead to increased viscosity (causing oil thickening problems), acidity (causing acidic corrosion), and formation of sludge and varnish (leading to filter plugging, fouling of critical oil clearances and valve friction). Monitoring of oxidation 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 and D6304), base reserve (Test Method D2896 and D4739), acid number tests (Test Methods D664 and D974) and other FT-IR oil analysis methods for nitration (Practice E2412), sulfate by-products (Test Method D7415), additive depletion (Test Method D7412), breakdown products and external contaminants (Practice E2412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to oxidation.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of oxidation products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants react with oxygen in the air to form a number of different chemical species, including aldehydes, ketones, esters, and carboxylic acids. This test method is designed as a fast, simple spectroscopic check for monitoring of oxidation 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 oxidation in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring oxidation in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for oxidation 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 oxidation of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 oxidation 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 i...

SIGNIFICANCE AND USE
5.1 An increase in sulfate material can be an indicator of oil degradation caused by oxidation of sulfur in the oil and sulfur in fuel. It can also indicate the breakdown or oxidation of some key additives in the oil such as antiwear and extreme pressure additives as well as blow-by concerns. As oxidized sulfur from blow-by enters the lubricant, it will consume the overbase additive to generate sulfate by-products. Monitoring of sulfate by-products is therefore an important parameter in determining overall machinery health and in determining additive depletion 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, D2896, and D6304), base number tests (Test Methods D974 and D4739), and other FT-IR oil analysis methods for nitration (Practice E2412), oxidation (Test Method D7414), additive depletion (Test Method D7412), breakdown products and external contaminants (Practice E2412), which also assess elements of the oil’s condition, see Refs (1-6)
SCOPE
1.1 This test method covers monitoring sulfate by-products in in-service petroleum and hydrocarbon based diesel crankcase engine and motor oils that have a sulfur content of greater than 500 ppm. This test method should not be employed when low-sulfur fuels are used for combustion.  
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Sulfate by-products can result from the introduction of sulfur from combustion or from the oxidation of sulfur-containing base oil additives. This test method is designed as a fast, simple spectroscopic check for monitoring of sulfate by-products 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 sulfate by-products in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring sulfate by-products in in-service oil and lubricant samples is described in Practice D7418. In this test method, measurement and data interpretation parameters for sulfate by-products 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 sulfate by-products of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).2  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.  
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).  
1.4.3 In either case, 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 sulfate by-product 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 T...

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity, which is usually a consideration for diesel engines, although it may also be an indicator of carburetor or injector problems in other fuel systems. Monitoring of soot 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 D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), 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 pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels 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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric (TGA) analysis described in Standard Method D5967, Annex A4.  
1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This inter...

SIGNIFICANCE AND USE
5.1 This test method provides a means for obtaining useful in-service fluid analysis properties in the field. It is not to be confused with laboratory or portable FTIR devices which provide measurements per the existing Test Methods listed in 4.1.1.1. Each of these monitored properties has been shown over time to indicate either contamination in the fluid system or a particular breakdown modality of the fluid, which is critical information to assess the health of the fluid as well as the machinery. By utilizing the field device, it is possible for those operating machinery, in locations and situations where it is not practical to gather a sample for the laboratory, to obtain quality in-service fluid analysis. This may be due to the need to have an analysis done in real-time, on-the-spot to maximize the operational hours of equipment, or to have the analysis performed at a location where no laboratory analysis is available.
SCOPE
1.1 This test method describes the use of a grating spectrometer to analyze properties of an in-service fluid sample which are indicative of the status of that fluid and related machinery.  
1.2 This test method provides a means for the assessment of in-service fluid properties using infrared spectroscopy. It describes a methodology for sampling, performing analysis, and providing key in-service fluid properties with a self-contained unit that is meant for field use. It provides analysis of in-service fluids at any stage of their useful life, including newly utilized fluid.  
1.3 In particular, these key in-service fluid properties include oxidation, nitration, sulfation, soot, and antiwear additives. They are applicable for hydrocarbon type (API Group I-IV) fluids from machinery lubricants, including reciprocating engine oils, turbine oils, hydraulic oils, and gear oils.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4.1 Exception—The unit for wavenumbers is in cm-1.  
1.5 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.

SIGNIFICANCE AND USE
4.1 This practice describes to the end user how to collect the FT-IR spectra of in-service oil samples for in-service oil condition monitoring. Various in-service oil condition monitoring parameters, such as oxidation, nitration, soot, water, ethylene glycol, fuel dilution, gasoline dilution, sulfate by-products and phosphate antiwear additives, can be measured by FT-IR spectroscopy (5-8), as described in Practice E2412. Changes in the values of these parameters over operating time can then be used to help diagnose the operational condition of various machinery and equipment and to indicate when an oil change should take place. This practice is intended to give a standardized configuration for FT-IR instrumentation and operating parameters employed in in-service oil condition monitoring in order to obtain comparable between-instrument and between-laboratory data.
SCOPE
1.1 This practice covers the instrument set-up and operation parameters for using FT-IR spectrometers for in-service oil condition monitoring for both direct trend analysis and differential trend analysis approaches.  
1.2 This practice describes how to acquire the FT-IR spectrum of an in-service oil sample using a standard transmission cell and establishes maximum allowable spectral noise levels.  
1.3 Measurement and integrated parameters for individual in-service oil condition monitoring components and parameters are not described in this practice and are described in their respective test methods.  
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.5 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.

SIGNIFICANCE AND USE
5.1 An increase in soot material can lead to increased wear, filter plugging and viscosity, which is usually a consideration for diesel engines, although it may also be an indicator of carburetor or injector problems in other fuel systems. Monitoring of soot 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 D7414), sulfate by-products (Test Method D7415), nitration (Test Method D7624), 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 pertains to field-based monitoring soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of in-service fuels.  
1.2 This test method uses FT-IR spectroscopy for monitoring of soot build-up in in-service lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate 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 soot in in-service lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.  
1.3 Acquisition of FT-IR spectral data for measuring soot in in-service oil and lubricant samples is described in Standard Practice D7418. In this test method, measurement and data interpretation parameters for soot 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 soot in in-service lubricants. For direct trend analysis, values are recorded directly from absorbance spectra and reported in units of 100*absorbance per 0.1 mm pathlength. 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 centimeter). 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).2 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 soot levels 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 primarily for petroleum/hydrocarbon based lubricants but is also applicable for ester based oils, including polyol esters or phosphate esters.  
1.6 This method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric (TGA) analysis described in Standard Method D5967, Annex A4.  
1.7 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.

SIGNIFICANCE AND USE
5.1 The PAI is representative of the quantity of all the compounds containing a carbonyl function that have formed by the oxidation of the lubricant (aldehydes, ketones, carboxylic acids, esters, anhydrides, etc.). The PAI gives representative information on the chemical degradation of the lubricant which has been caused by oxidation.  
5.2 This test method was developed for transmission oils and is used in the CEC L-48-A-00 test (Oxidation Stability of Lubricating Oils Used in Automotive Transmissions by Artificial Aging) as a parameter for the end of test evaluation.
SCOPE
1.1 This test method covers the determination of the oxidation of used lubricants by FT-IR (Fourier Transform Infrared Spectroscopy). It measures the concentration change of constituents containing a carbonyl function that have formed during the oxidation of the lubricant.  
1.2 This test method may be used to indicate relative changes that occur in an oil under oxidizing conditions. The test method is not intended to measure an absolute oxidation property that can be used to predict performance of an oil in service.  
1.3 This test method was developed for transmission oils which have been degraded either in service, or in a laboratory test, for example a bulk oxidation test. It may be used for other in-service oils, but the stated precision may not apply.  
1.4 The results of this test method may be affected by the presence of other components with an absorbance band in the zone of 1600–1800 cm-1. Low PAI values may be difficult to determine in those cases. Section 6 describes these possible interferences in more detail.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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.

SIGNIFICANCE AND USE
This test method provides a simple field-based technique for condition monitoring of soot in in-service lubricants associated with combustion engines, machinery, and equipment used in industry and by the military. Critical applications should use laboratory based test methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4. Infrared spectroscopy is a well established laboratory method for evaluating soot levels in lubricants. This test method can be used to monitor soot build-up in lubricants and can indicate whether soot has accumulated to an extent which could significantly degrade the performance of the oil. High soot content can compromise lubricant performance and cause filter and oil passage blockage. Soot concentration should be considered in conjunction with data from other condition monitoring tests as described in Practice E2412 to determine whether the oil should be replaced to minimize machinery wear or failure, or both.
SCOPE
1.1 This test method pertains to field-based monitoring of soot in diesel crankcase engine oils as well as in other types of engine oils where soot may contaminate the lubricant as a result of a blow-by due to incomplete combustion of fuels. It is applicable to oils having soot levels of up to 12%.
1.2 This test method uses filter-based infrared technology for monitoring of soot build-up in in-service petroleum and hydrocarbon-based lubricants as a result of normal machinery operation. Soot levels in engine oils rise as soot particles contaminate the oil as a result of exhaust gas recirculation from blow-by. This test method is designed as a fast, simple and field capable spectroscopic check for soot in in-service hydrocarbon-based lubricants with the objective of helping diagnose the operational condition of the machine based on measuring the level of soot in the oil.
1.3 This test method is intended as a field test only, and should be treated as such. Critical applications should use laboratory based methods, such as Thermal Gravimetric Analysis (TGA) described in Test Method D5967, Annex A4.
1.4 Acquisition of spectral data for measuring soot in in-service oil and lubricant samples with the use of a fixed-filter IR instrument is described in this test method. Calibration against prepared soot standards is also described.
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 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.

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...

SIGNIFICANCE AND USE
Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health. Atomic emission (AE) and atomic absorption (AA) spectroscopy are often employed for wear metal analysis (for example, Test Method D5185). A number of physical property tests complement wear metal analysis and are used to provide information on lubricant condition (for example, Test Methods D445, D2896, and D6304). Molecular analysis of lubricants and hydraulic fluids by FT-IR spectroscopy produces direct information on molecular species of interest, including additives, fluid breakdown products and external contaminants, and thus complements wear metal and other analyses used in a condition monitoring program (1,3-7).
SCOPE
1.1 This practice covers the use of FT-IR in monitoring additive depletion, contaminant buildup and base stock degradation in machinery lubricants, hydraulic fluids and other fluids used in normal machinery operation. Contaminants monitored include water, soot, ethylene glycol, fuels and incorrect oil. Oxidation, nitration and sulfonation of base stocks are monitored as evidence of degradation. The objective of this monitoring activity is to diagnose the operational condition of the machine based on fault conditions observed in the oil. Measurement and data interpretation parameters are presented to allow operators of different FT-IR spectrometers to compare results by employing the same techniques.
1.2 This practice is based on trending and distribution response analysis from mid-infrared absorption measurements. While calibration to generate physical concentration units may be possible, it is unnecessary or impractical in many cases. Warning or alarm limits (the point where maintenance action on a machine being monitored is recommended or required) can be determined through statistical analysis, history of the same or similar equipment, round robin tests or other methods in conjunction with correlation to equipment performance. These warning or alarm limits can be a fixed maximum or minimum value for comparison to a single measurement or can also be based on a rate of change of the response measured (1). This practice describes distributions but does not preclude using rate-of-change warnings and alarms.
Note 1—It is not the intent of this practice 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.
1.3 Spectra and distribution profiles presented herein are for illustrative purposes only and are not to be construed as representing or establishing lubricant or machinery guidelines.
1.4 This practice is designed as a fast, simple spectroscopic check for condition monitoring of in-service lubricants and can be used to assist in the determination of general machinery health through measurement of properties observable in the mid-infrared spectrum such as water, oil oxidation, and others as noted in 1.1. The infrared data generated by this practice is typically used in conjunction with other testing methods. For example, infrared spectroscopy cannot determine wear metal levels or any other type of elemental analysis. The practice as presented is not intended for the prediction of lubricant physical properties (for example, viscosity, total base number, total acid number, etc.). This practice is designed for monitoring in-service lubricants and can aid in the determination of general machinery health and is not designed for the analysis of lubricant composition, lubricant performance or additive package formulations.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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 t...

SIGNIFICANCE AND USE
Antiwear additives are commonly used in petroleum and hydrocarbon based lubricants to prevent machinery wear by forming a chemical barrier activated by frictional heat. Antiwear additives that are phosphate based can be measured by FT-IR spectroscopy using the phosphate absorption band. Initially, phosphate antiwear additives will decompose and form a protective film by binding to metal surfaces and through oxidative mechanisms, and so a decrease in the level of phosphate antiwear additive relative to that in the new oil is expected during normal machinery operation. Subsequently, significant depletion of phosphate antiwear additives due to oxidation or hydrolysis can occur when the lubricant is subjected to high temperatures and high levels of moisture. This usually occurs prior to the point where the oxidation of the lubricant begins to accelerate—making trending of phosphate antiwear additives a useful indicator of the lubricant’s remaining in-service life. Monitoring of phosphate antiwear additive depletion 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 D 5185), physical property tests (Test Methods D 445, D 2896, and D 6304) and other FT-IR oil analysis methods for oxidation (Test Method D 7414), sulfate by-products (Test Method D 7415), nitration, breakdown products and external contaminants (Practice E 2412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants such as various types of engine oils, hydraulic oils, and other lubricants that are formulated for protection against wear. Typical phosphate antiwear additives include zinc dialkyldithiophosphates, trialkyl phosphates and triaryl phosphates.
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring of phosphate antiwear additive depletion in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Monitoring the depletion of phosphate antiwear additives in in-service lubricants can indicate unusual wear or severe operating conditions of the machine. This test method is designed as a fast, simple spectroscopic check for monitoring of phosphate antiwear additives 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 phosphate antiwear additives in the oil.
1.3 Acquisition of FT-IR spectral data for measuring phosphate antiwear additives in in-service oil and lubricant samples is described in Practice D 7418. In this test method, measurement and data interpretation parameters for phosphate antiwear additives 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 phosphate antiwear additives in in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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 centimeter).
1.4.3 In either case, maintenance action limits should be determined through statisti...

SIGNIFICANCE AND USE
An increase in sulfate material can be an indicator of oil degradation caused by oxidation of sulfur in the oil and sulfur in fuel. It can also indicate the breakdown or oxidation of some key additives in the oil such as antiwear and extreme pressure additives as well as blow-by concerns. As oxidized sulfur from blow-by enters the lubricant, it will consume the overbase additive to generate sulfate by-products. Monitoring of sulfate by-products is therefore an important parameter in determining overall machinery health and in determining additive depletion 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 D 5185), physical property tests (Test Methods D 445, D 2896, and D 6304), base number tests (Test Methods D 974 and D 4739) and other FT-IR oil analysis methods for nitration (Practice E 2412), oxidation (Test Method D 7414), additive depletion (Test Method D 7412), breakdown products and external contaminants (Practice E 2412), which also assess elements of the oil’s condition, see Refs (1-6)
SCOPE
1.1 This test method covers monitoring sulfate by-products in in-service petroleum and hydrocarbon based diesel crankcase engine and motor oils that have a sulfur content of greater than 500 ppm. This test method should not be employed when low-sulfur fuels are used for combustion.
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Sulfate by-products can result from the introduction of sulfur from combustion or from the oxidation of sulfur-containing base oil additives. This test method is designed as a fast, simple spectroscopic check for monitoring of sulfate by-products 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 sulfate by-products in the oil.
1.3 Acquisition of FT-IR spectral data for measuring sulfate by-products in in-service oil and lubricant samples is described in Practice D 7418. In this test method, measurement and data interpretation parameters for sulfate by-products 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 sulfate by-products of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).
1.4.3 In either case, 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 sulfate by-product 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 v...

SIGNIFICANCE AND USE
A large number of compounds, such as aldehydes, ketones, esters, and carboxylic acids, are produced when oils react with atmospheric oxygen. Oxidation is measured using a common FT-IR spectral feature between 1800 and 1670 cm-1 caused by the absorption of the carbonyl group present in most oxidation compounds. These oxidation products may lead to increased viscosity (causing oil thickening problems), acidity (causing acidic corrosion), and formation of sludge and varnish (leading to filter plugging, fouling of critical oil clearances and valve friction). Monitoring of oxidation 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 D 5185), physical property tests (Test Methods D 445 and D 6304), base reserve (Test Method D 2896 and D 4739), acid number tests (Test Methods D 664 and D 974) and other FT-IR oil analysis methods for nitration (Practice E 2412), sulfate by-products (Test Method D 7415), additive depletion (Test Method D 7412), breakdown products and external contaminants (Practice E 2412), which also assess elements of the oil’s condition, see Refs (1-6).
SCOPE
1.1 This test method covers monitoring oxidation in in-service petroleum and hydrocarbon based lubricants such as in diesel crankcase, motor, hydraulic, gear and compressor oils, as well as other types of lubricants that are prone to oxidation.
1.2 This test method uses Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of oxidation products in in-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Petroleum and hydrocarbon based lubricants react with oxygen in the air to form a number of different chemical species, including aldehydes, ketones, esters, and carboxylic acids. This test method is designed as a fast, simple spectroscopic check for monitoring of oxidation 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 oxidation in the oil.
1.3 Acquisition of FT-IR spectral data for measuring oxidation in in-service oil and lubricant samples is described in Practice D 7418. In this test method, measurement and data interpretation parameters for oxidation 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 oxidation of in-service petroleum and hydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum value for a single measurement or, alternatively, can be based on a rate of change of the response measured, see Ref (1).  
1.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1 mm pathlength.
1.4.2 For differential trend analysis, values are recorded from the differential spectra (spectrum obtained by subtraction of the absorption 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).
1.4.3 In either case, 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 oxidation 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...