1、Designation: D7415 09D7415 18Standard Test Method forCondition Monitoring of Sulfate By-Products in In-ServicePetroleum and Hydrocarbon Based Lubricants by TrendAnalysis Using Fourier Transform Infrared (FT-IR)Spectrometry1This standard is issued under the fixed designation D7415; the number immedia
2、tely following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1
3、This test method covers monitoring sulfate by-products in in-service petroleum and hydrocarbon based diesel crankcaseengine and motor oils that have a sulfur content of greater than 500 ppm.This test method should not be employed when low-sulfurfuels are used for combustion.1.2 This test method uses
4、 Fourier Transform Infrared (FT-IR) spectrometry for monitoring build-up of sulfate by-products inin-service petroleum and hydrocarbon based lubricants as a result of normal machinery operation. Sulfate by-products can resultfrom the introduction of sulfur from combustion or from the oxidation of su
5、lfur-containing base oil additives. This test method isdesigned as a fast, simple spectroscopic check for monitoring of sulfate by-products in in-service petroleum and hydrocarbon basedlubricants with the objective of helping diagnose the operational condition of the machine based on measuring the l
6、evel of sulfateby-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 inPractice D7418. In this test method, measurement and data interpretation parameters for sulfate by-products using both direct trendana
7、lysis 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 andhydrocarbon based lubricants. Warnings or alarm limits can be set on the basis of a fixed minimum va
8、lue for a single measurementor, alternatively, can be based on a rate of change of the response measured, see Ref (1).21.4.1 For direct trend analysis, values are recorded directly from absorption spectra and reported in units of absorbance per 0.1mm pathlength.1.4.2 For differential trend analysis,
9、 values are recorded from the differential spectra (spectrum obtained by subtraction of theabsorption spectrum of the reference oil from that of the in-service oil) and reported in units of 100*absorbance per 0.1 mmpathlength (or equivalently absorbance units per centimetre).1.4.3 In either case, ma
10、intenance action limits should be determined through statistical analysis, history of the same or similarequipment, round robin tests, or other methods in conjunction with the correlation of sulfate by-product changes to equipmentperformance.NOTE 1It is not the intent of this test method to establis
11、h or recommend normal, cautionary, warning, or alert limits for any machinery. Such limitsshould 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 f
12、or ester based oils, includingpolyol 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 ExceptionThe unit for wave numbers is cm-1.1.7 This standard does not purport to address all of the safe
13、ty concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1 This test method is under the jurisdiction ofAS
14、TM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.96.03 on FTIR Testing Practices and Techniques Related to In-Service Lubricants.Current edition approved July 1, 2009Jan. 1, 2018. Published August 2009March 2018. Originally appr
15、oved in 2009. Last previous edition approved in 2009 asD7415 09. DOI: 10.1520/D7415-09.10.1520/D7415-18.2 The boldface numbers in parentheses refer to a list of references at the end of this standard.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard a
16、n indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is t
17、o be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.8 This international standard was developed in accordance with internationally re
18、cognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D445 Test Method for
19、 Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)D974 Test Method for Acid and Base Number by Color-Indicator TitrationD2896 Test Method for Base Number of Petroleum Products by Potentiometric Perchloric Acid TitrationD4739 Test Method for Base Number Dete
20、rmination by Potentiometric Hydrochloric Acid TitrationD5185 Test Method for Multielement Determination of Used and Unused Lubricating Oils and Base Oils by InductivelyCoupled Plasma Atomic Emission Spectrometry (ICP-AES)D6304 Test Method for Determination of Water in Petroleum Products, Lubricating
21、 Oils, and Additives by Coulometric KarlFischer TitrationD7412 Test Method for Condition Monitoring of PhosphateAntiwearAdditives in In-Service Petroleum and Hydrocarbon BasedLubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) SpectrometryD7414 Test Method for Condition Monitoring
22、of Oxidation in In-Service Petroleum and Hydrocarbon Based Lubricants byTrend Analysis Using Fourier Transform Infrared (FT-IR) SpectrometryD7418 Practice for Set-Up and Operation of Fourier Transform Infrared (FT-IR) Spectrometers for In-Service Oil ConditionMonitoringE131 Terminology Relating to M
23、olecular SpectroscopyE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE2412 Practice for Condition Monitoring of In-Service Lubricants by TrendAnalysis Using Fourier Transform In
24、frared (FT-IR)Spectrometry3. Terminology3.1 DefinitionsFor definitions of terms relating to infrared spectroscopy used in this test method, refer to Terminology E131.For definitions of terms related to in-service oil condition monitoring, refer to Practice D7418.3.2 machinery health, nqualitative ex
25、pression of the operational status of a machine subcomponent, component, or entiremachine, used to communicate maintenance and operational recommendations or requirements in order to continue operation,schedule maintenance, or take immediate maintenance action.4. Summary of Test Method4.1 This test
26、method uses FT-IR spectrometry to monitor sulfate by-product in in-service petroleum and hydrocarbon basedlubricants. The FT-IR spectra of in-service oil samples are collected according to the protocol for either direct trend analysis ordifferential trend analysis described in Practice D7418, and th
27、e levels of sulfate by-products are measured using the peak heightor area measurements described herein.5. Significance and Use5.1 An increase in sulfate material can be an indicator of oil degradation caused by oxidation of sulfur in the oil and sulfur infuel. It can also indicate the breakdown or
28、oxidation of some key additives in the oil such as antiwear and extreme pressureadditives as well as blow-by concerns.As oxidized sulfur from blow-by enters the lubricant, it will consume the overbase additiveto generate sulfate by-products. Monitoring of sulfate by-products is therefore an importan
29、t parameter in determining overallmachinery health and in determining additive depletion and should be considered in conjunction with data from other tests suchas atomic emission (AE) and atomic absorption (AA) spectroscopy for wear metal analysis (Test Method D5185), physicalproperty tests (Test Me
30、thods D445, D2896, and D6304), base number tests (Test Methods D974 and D4739), and other FT-IR oilanalysis methods for nitration (Practice E2412), oxidation (Test Method D7414), additive depletion (Test Method D7412),breakdown products and external contaminants (Practice E2412), which also assess e
31、lements of the oils condition, see Refs (1-6)6. Interferences6.1 Various additive packages, especially those containing detergents, dispersants, demulsifiers and overbase additives, willinterfere with the sulfate by-products measurement.6.2 Contaminants such as esters, polyols, glycols, and alcohols
32、 will also interfere with the measurement of sulfate by-products.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM webs
33、ite.D7415 1826.3 Oxidation by-products can be a major source of interference in the measurement of sulfate by-products. Because of thisinterference, the low levels of sulfate by-products associated with the use of low-sulfur fuels for combustion cannot be adequatelymeasured.7. Apparatus7.1 Fourier t
34、ransform infrared spectrometer equipped with sample cell, filter (optional) and pumping system (optional) asspecified in Practice D7418.7.2 FT-IR Spectral Acquisition ParametersSet FT-IR spectral acquisition parameters according to instructions in PracticeD7418.8. Sampling8.1 Obtain a sample of the
35、in-service oil and a sample of the reference oil (required only for differential trend analysis)according to the protocol described in Practice D7418.9. Preparation and Maintenance of Apparatus9.1 Rinse, flush, and clean the sample cell, inlet lines, and inlet filter according to instructions in Pra
36、ctice D7418.9.2 Monitor cell pathlength as specified in Practice D7418.10. Procedure10.1 Collect a background spectrum according to the procedure specified in Practice D7418.10.2 Differential Trend Analysis OnlyCollect the absorption spectrum of a reference oil sample according to the procedurespeci
37、fied in Practice D7418.10.3 Collect the absorption spectrum of an in-service oil sample according to the procedure specified in Practice D7418.10.4 Data ProcessingAll data are normalized to a pathlength of 0.100 mm according to the procedure specified in PracticeD7418.11. Calculation11.1 Calculation
38、 of Sulfate By-Products Value:11.1.1 Procedure A (Direct Trend Analysis)Sulfate by-products value by the direct trending method is calculated from the oilsample spectrum using the measurement area and baseline points listed in Table 1. Fig. 1 illustrates the area used in themeasurement of sulfate by
39、-products in the spectrum of diesel crankcase oil.11.1.2 Procedure B (Differential Trend Analysis)Sulfate by-products value by the differential trending method is calculatedfrom the differential spectrum using the measurement peak and baseline points listed in Table 1. Fig. 2 illustrates the band us
40、edin the measurement of sulfate by-products in the differential spectrum of diesel crankcase oil.11.2 Sample CarryoverTo ensure the minimum amount of sample-to-sample cross-contamination or carryover, either aminimum volume of the subsequent sample or a solvent rinse should be used to flush out the
41、previous sample. The efficacy of theflushing protocol may be assessed by consecutively analyzing an oil having a low (or zero) sulfate by-product level (L1, forexample, a fresh oil) and a used oil sample having a high sulfate by-product level (H1) followed by a second run of the oil samplehaving a l
42、ow sulfate by-product level (L2) and then calculating the percent carryover (PC) as follows The calculated PC shouldbe less than 5%.5 %.PC5L22L1!/H1#3100 (1)where:L1, H1, and L2 = the values measured for sulfate by-products (using the parameters given in Table 1) for the samples run in theindicated
43、sequence.12. Report12.1 Procedure A (Direct Trend Analysis)Values are reported in units of absorbance/0.100 mm.TABLE 1 Parameters for Measuring Sulfate By-Products in In-Service Petroleum and Hydrocarbon Based LubricantsMethod Measurement, cm-1 Baseline Point(s), cm-1Procedure A(Direct Trend Analysi
44、s)Area from1180 to 1120Minima 2200 to 1900and 650 to 550Procedure B(Differential Trend Analysis)Height at 1150 Single point at 1950D7415 18312.2 Procedure B (Differential Trend Analysis)Values are reported in units of absorbance per centimeter (Abs/cm), calculatedas follows:Sulfate By-Products in Ab
45、s/cm= Sulfate By-Products in Abs/0.100 mm * 10012.3 TrendingData shall be recorded and reported at selected time intervals during the lubricants life. Ideally, sulfateby-products values would be compared to that of the newly formulated oil and plotted over time to visualize the relative changesin su
46、lfate by-products and to determine when there needs to be an oil change, albeit other parameters may dictate this changeearlier. Sampling and reporting time intervals for sulfate by-products are based on the type of machinery and its previous historyassociated with this parameter.FIG. 1 Sulfate By-P
47、roducts Measurement in the Spectrum of a Diesel Crankcase Oil for Direct Trend Analysis (Procedure A)FIG. 2 Sulfate By-Products Measurement in the Differential Spectrum of a Petroleum Crankcase Lubricant for Differential Trend Analy-sis (Procedure B)D7415 18412.4 Statistical Analysis and Alarm Limit
48、sFor statistical analysis and setting alarm limits, refer to Practice E2412, Annex A3on “Distribution Profiles and Statistical Analysis.”12.5 Effects of Oil FormulationThe compositions of various oil formulations can have an effect on the results reported forsulfate by-products value, and values fro
49、m two different oil formulations should not be compared. Results should be interpretedrelative to values measured for unused oils of the same formulation or trended directly from the sample history.13. Precision and Bias (Interim)413.1 PrecisionThe precision of the test method has not yet been determined by a formal interlaboratory study. Preliminaryexaminations of repeatability have shown that the difference between repetitive results obtained by the same operator in a givenlaboratory applying the same test method with the same apparatus under constant op
