1、Designation: D7843 12D7843 16Standard Test Method forMeasurement of Lubricant Generated Insoluble ColorBodies in In-Service Turbine Oils using Membrane PatchColorimetry1This standard is issued under the fixed designation D7843; the number immediately following the designation indicates the year ofor
2、iginal 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 This test method extracts insoluble contaminants from
3、a sample of in-service turbine oil onto a patch and the color of themembrane patch is analyzed by a spectrophotometer. The results are reported as a E value, within the CIE LAB scale.1.2 This test method is not appropriate for turbine oils with dyes.1.3 The values stated in SI units are to be regard
4、ed as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determi
5、ne the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD4378 Practice for In-Service Monitoring of Mineral Tur
6、bine Oils for Steam, Gas, and Combined Cycle TurbinesE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Using the CIE SystemE691 Practice for Conducting an Interlaboratory Study to Determine the
7、 Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 CIELAB color scales, nCIE 1976 L*, a*, b* opponent-color scales, in which a* is positive in the red direction andnegative in the green direction; b* is positive in the yellow direction and negative in the blue direction; and L* is positi
8、ve in thelightness direction and negative in the darkness direction. E3083.1.2 colorimetry, nthe science of color measurement. E2843.1.3 in-service oil, nlubricating oil that is present in a machine that has been at operating temperature for at least one hour(for example, an engine, gearbox, transfo
9、rmer, or turbine).3.1.4 membrane color, na visual rating of particulate on a filter membrane against ASTM Color Standards.3.1.5 membrane filter, na porous article of closely controlled pore size through which a liquid is passed to separate matter insuspension.3.2 Definitions of Terms Specific to Thi
10、s Standard:3.2.1 varnish, na thin, hard, lustrous, oil-insoluble deposit, composed primarily of organic residue, and most readily definableby color intensity. It is not easily removed by wiping with a clean, dry, soft, lint-free wiping material and is resistant to saturatedsolvents. Its color may va
11、ry, but it usually appears in gray, brown, or amber hues.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.C0.01 on Turbine Oil Monitoring, Problems and Systems.Current edition app
12、roved Dec. 1, 2012June 1, 2016. Published January 2013August 2016. Originally approved in 2012. Last previous edition approved in 2012 asD7843 12. DOI: 10.1520/D7843-12.10.1520/D7843-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceast
13、m.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becaus
14、eit 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 to be considered the official document.*A Summary of Changes section appears
15、 at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 Insoluble deposits are extracted from an in-service turbine oil sample using a 47 mm, 0.45-micron 47 mm, 0.45 mmembrane nitro-cel
16、lulose patch. The color of the patch is then analyzed using a spectrophotometer and the results are reported asa E value in the CIE LAB scale.5. Significance and Use5.1 This test can be a guide to end-users on the formation of lubricant-generated, insoluble deposits.5.2 The results from this test ar
17、e intended to be used as a condition monitoring trending tool as part of a comprehensiveprogram, as outlined in standards such as Practice D4378.6. Apparatus6.1 Variations of apparatus, particularly with respect to filter membranes and vacuum pump setting, can affect the test resultssignificantly.6.
18、2 When the user of this test method uses an alternate membrane filter, it is incumbent upon them to establish that the alternatefilter will give equal results.6.3 Required Apparatus:6.3.1 Membrane Filter, 47 mm 47 mm nitro-cellulose, 0.45-m.0.45 m.6.3.2 Forceps, smooth-tip.6.3.3 Borosilicate Filter
19、Holder.6.3.4 Borosilicate Filtering Flask.6.3.5 Wash Bottle equipped with 0.22 micron 0.22 m membranes.6.3.6 Vacuum Source, capable of maintaining a vacuum of 71 kPa 6 5 kPa.71 kPa 6 5 kPa.6.3.7 Graduated cylinder, 150200 mL.150 mL to 200 mL.6.3.8 Beaker, 100250 mL.100 mL to 250 mL.6.3.9 Petri dish.
20、6.3.10 Spectrophotometer, with capabilities of analyzing a standard 15 mm 15 mm target with a 0/45 measuring geometry, 10observer, 10 nm 10 nm spectral intervals minimum resolution, the visible spectral range of 400700 nm 400 nm to 700 nm andCIELAB measuring indices.7. Reagents and Materials7.1 Petr
21、oleum Spirit (also known as petroleum ether or IP Petroleum Spirit 40/60) (WarningExtremely flammable. Harmfulif inhaled. Vapors are easily ignited by electrostatic discharges, causing flash fire.), having boiling range from 3535 C to60C.60 C.7.2 Coleman Camp FuelColeman Fuel is a complex mixture of
22、 light hydrocarbons (primarily aliphatic) produced bydistillation of petroleum. Carbon number range is C5C5 to C9,C9, and contains less than 0.001%0.001 % benzene.7.3 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents con
23、form to the specifications of the Committee of Analytical Reagents of the American Chemical Society where suchspecifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of th
24、e determination.8. Sampling, Test Specimens, and Test Units8.1 Using either Practice D4057 (manual sampling) or Practice D4177 (automatic sampling), obtain a representative sample ofat least 60 mL 60 mL of the material to be tested. The preferred sample container is an amber or other dark colored bo
25、ttle tominimize potential UV reactions to the sample. Translucent or clear bottles can be used as long as the sample is protected fromUV exposure.NOTE 1The sample container used shall preclude exposure to UV light as oil is known to be sensitive to both indoor and outdoor sources. Fluorescentlight i
26、s known to contain UV components and has been shown to increase deposit levels. This exposure can occur upon drawing of the sample as wellas during incubation period. Wide-mouth laboratory quality amber high-density polyethylene (HDPE) bottles have been shown to protect the oil samplefrom UV light e
27、xposure. Other translucent or clear sample bottles are acceptable for use provided that the sample bottle, upon drawing of the sample andthroughout the heating/incubation process, is immediately placed and stored into packaging or a storage unit that blocks light. Cylindrical cardboardpackaging cont
28、ainers meet this intent.8.2 The sample shall be heated to 6065C for 2325 h 60 C to 65 C for 23 h to 25 h then stored between 1525C, 15 Cto 25 C, away from UV light for an incubation period of 6876 hours. 68 h to 76 h. Samples that are analyzed prior to this agingperiod may produce fewer color bodies
29、 on the patch; thus, producing a lower E value, and may lower the value of trend analysis.NOTE 2Samples can be analyzed in longer or shorter intervals with agreement of the end-user. The level of deposit and as a consequence, the testresults may be affected by time duration chosen. It is sometimes s
30、uggested to additionally analyze the sample at multiple incubation periods to fullyunderstand the operating system.D7843 1629. Procedure9.1 Preparation of Sample and Materials:9.1.1 Document the date and time at the beginning of the test.9.1.2 Vigorously mix the sample for 15 s 15 s minimum to resus
31、pend insolubles uniformly. Visually inspect the inside of thebottle for evidence of material adherent to the surface of the bottle before sampling.NOTE 3If adherent material cannot be removed from bottle after repeated attempts to vigorously mix, include as comment in the reportingdocumentation.9.1.
32、3 Transfer 50 mL 6 1 mL 50 mL 6 1 mL of sample into clean beaker or Erlenmeyer flask.9.1.4 Add approximately 50 mL 6 1 mL 50 mL 6 1 mL of petroleum ether to beaker containing sample.9.1.5 Stir sample for approximately 30 s 30 s to ensure that a complete solution (and complete mixing) is attained.9.1
33、.6 Pour sample into filter funnel within 12 minutes 1 min to 2 min of initial mixing.9.2 Filtration Process:9.2.1 Using forceps, mount the filter on the center of the filter holder.9.2.2 Mount and securely clamp the filter funnel to the filter.9.2.3 Apply a vacuum and ensure a vacuum of less than 76
34、 kPa 76 kPa is attained and held.9.2.4 Rinse the beaker twice with a minimum of 35 mL 35 mL of petroleum ether and pour the rinsing into the filter funnel.9.2.5 Permit the filtrate to completely flow through.9.2.6 Carefully, remove the clamp and funnel. Wash any adhering insolubles from the funnel o
35、nto the membrane with petroleumether. Wash the membrane gently, particularly the edges, with petroleum ether from the wash bottle.NOTE 4If any of the deposits fails to remain on (or falls off) the dry membrane the test must be repeated.9.2.7 Carefully release the vacuum.9.2.8 Remove the clamp and fi
36、lter holder.9.2.9 Using forceps carefully remove the filter from the filter holder and place into a clean dry petri-dish. To facilitate handling,the membrane filters might be rested on clean glass rods in the petri-dish.9.2.10 Dry the membrane by placing it in a low-level heat source free of ignitio
37、n sources for flammable vapors, or air dry(typically, 3 h) 3 h) in a dust-free location. Dryness can be estimated by comparing the white color of the outer edge of the testmembrane with a new membrane.9.3 Color Determination of the Membrane Patch:9.3.1 Standardize the instrument using a patch develo
38、ped from clean solvent application of the method to establish thebackground color white.9.3.2 Follow the standardization procedure defined by the instrument manufacturer.9.3.3 Analyze the patch as recommended by the instrument manufacturer.9.3.4 Analyze the color of the patch in accordance with the
39、equipment manufacturers instructions to produce a CIE LAB value.10. Calculation of Results10.1 CIE 1976 L* a* b* Uniform Color Space and Color-Difference EquationThis is an approximately uniform color spaceSystem defined by Practice E308. It is produced by plotting in rectangular coordinates the qua
40、ntities L*, a*, b*, calculated asfollows:L*5116*Y Yn !13 2 16 (1)a*5500X Xn !13 2 Y Yn!13# (2)b*5200Y Yn !13 2 Z Zn!13# (3)XXn ;YYn ; ZZn.0.01 (4)TABLE 1 72-hours (3-Day)72 h (3 day)Material AverageRepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx
41、sr sR r RSample 1 15.332 0.861 3.169 2.410 8.874Sample 2 7.409 0.910 2.830 2.547 7.925Sample 3 6.970 0.839 3.085 2.349 8.637Sample 4 3.472 0.468 2.047 1.309 5.732Sample 5 6.993 0.852 2.968 2.386 8.309Sample 6 34.258 3.656 11.556 10.236 32.357Sample 7 3.475 0.176 1.647 0.494 4.611D7843 163The tristim
42、ulus values Xn,Yn,Zn define the color of the normally white object-color stimulus, in this case the new membranepatch. Under these conditions, Xn,Yn, and Zn are the tristimulus values of the standard 10 observer, D65 illuminant.10.1.1 The total difference E*ab between two colors each given in terms
43、of L*, a*, b* is calculated as follows:E*ab 5L *!2 1a *!2 1b *!2 #12 (5)10.2 Reporting:10.2.1 Report the spectrophotometer CIE LAB E values to one decimal place.10.2.2 The incubation after heating shall be reported with the E value.10.2.3 Note in the reporting documentation any deviation from this S
44、tandards methodology.11. Precision and Bias311.1 The precision of this test method is based on an interlaboratory study conducted in 2011. Twelve laboratories participatedin the study, testing seven different turbine oils, over three and five day periods. Every analyst was instructed to report dupli
45、catetest results in this study. Practice E691 was followed for the study design; the details are given in ASTM Research ReportRR:D02-1752.11.1.1 Repeatability limit (r)Two test results obtained within one laboratory shall be judged not equivalent if they differ bymore than the “r” value for that mat
46、erial; “r” is the interval representing the critical difference between two test results for the samepoint, obtained by the same operator using the same equipment on the same day in the same laboratory.11.1.1.1 Repeatability limits are listed in Tables 1 and 2.11.1.2 Reproducibility limit (R)Two tes
47、t results shall be judged not equivalent if they differ by more than the “R” value forthat material; “R” is the interval representing the critical difference between two test results for the same point, obtained bydifferent operators using different equipment in different laboratories.11.1.2.1 Repro
48、ducibility limits are listed in Tables 1 and 2.11.1.3 The above terms (repeatability limit and reproducibility limit) are used as specified in Practice E177.11.1.4 Any judgment in accordance with statements 9.1.1 and 9.1.2 would have an approximate 95%95 % probability of beingcorrect.11.2 BiasAt the
49、 time of the study, there was no accepted reference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.11.3 The precision statement was determined through statistical examination of 312 test results, from a total of twelvelaboratories, on seven turbine oils. The seven materials were described as:Sample 1: 2011Sept-1, 3-day heating experiment for the 3-daywait after heating + 2011Sept-1, 5-day heating experiment for the5-day wait after heat
