ASTM D7843-12

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7843 − 12
StandardTest Method for
Measurement of Lubricant Generated Insoluble Color
Bodies in In-Service Turbine Oils using Membrane Patch
Colorimetry
This standard is issued under the fixed designation D7843; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 CIELAB color scales, n—CIE 1976 L*, a*, b*
opponent-color scales, in which a* is positive in the red
1.1 This test method extracts insoluble contaminants from a
direction and negative in the green direction; b* is positive in
sample of in-service turbine oil onto a patch and the color of
the yellow direction and negative in the blue direction; and L*
the membrane patch is analyzed by a spectrophotometer. The
is positive in the lightness direction and negative in the
results are reported as a∆E value, within the CIE LAB scale.
darkness direction. E308
1.2 This test method is not appropriate for turbine oils with
3.1.2 colorimetry, n—the science of color measurement.
dyes.
E284
1.3 This standard does not purport to address all of the
3.1.3 in-service oil, n—lubricating oil that is present in a
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- machine that has been at operating temperature for at least one
priate safety and health practices and determine the applica- hour(forexample,anengine,gearbox,transformer,orturbine).
bility of regulatory limitations prior to use.
3.1.4 membrane color, n—a visual rating of particulate on a
filter membrane against ASTM Color Standards.
2. Referenced Documents
3.1.5 membrane filter, n—a porous article of closely con-
2.1 ASTM Standards:
trolled pore size through which a liquid is passed to separate
D4057 Practice for Manual Sampling of Petroleum and
matter in suspension.
Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and
3.2 Definitions of Terms Specific to This Standard:
Petroleum Products
3.2.1 varnish, n—a thin, hard, lustrous, oil-insoluble
D4378 Practice for In-Service Monitoring of Mineral Tur-
deposit, composed primarily of organic residue, and most
bine Oils for Steam, Gas, and Combined Cycle Turbines
readily definable by color intensity. It is not easily removed by
E177 Practice for Use of the Terms Precision and Bias in
wiping with a clean, dry, soft, lint-free wiping material and is
ASTM Test Methods
resistant to saturated solvents. Its color may vary, but it usually
E284 Terminology of Appearance
appears in gray, brown, or amber hues.
E308 PracticeforComputingtheColorsofObjectsbyUsing
the CIE System
4. Summary of Test Method
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
4.1 Insoluble deposits are extracted from an in-service
turbine oil sample using a 47 mm, 0.45-micron membrane
3. Terminology
nitro-cellulose patch. The color of the patch is then analyzed
3.1 Definitions: using a spectrophotometer and the results are reported as a∆E
value in the CIE LAB scale.
This test method is under the jurisdiction of ASTM Committee D02 on
5. Significance and Use
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.C0.01 on Turbine Oil Monitoring, Problems and Systems.
5.1 This test can be a guide to end-users on the formation of
Current edition approved Dec. 1, 2012. Published January 2013. DOI: 10.1520/
lubricant-generated, insoluble deposits.
D7843-12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.2 The results from this test are intended to be used as a
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
condition monitoring trending tool as part of a comprehensive
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. program, as outlined in standards such as Practice D4378.
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D7843 − 12
NOTE 1—Samples can be analyzed in longer or shorter intervals with
6. Apparatus
agreement of the end-user. The level of deposit and as a consequence, the
6.1 Variations of apparatus, particularly with respect to filter
test results may be affected by time duration chosen. It is sometimes
membranes and vacuum pump setting, can affect the test
suggested to additionally analyze the sample at multiple incubation
periods to fully understand the operating system.
results significantly.
6.2 When the user of this test method uses an alternate
9. Procedure
membrane filter, it is incumbent upon them to establish that the
9.1 Preparation of Sample and Materials:
alternate filter will give equal results.
9.1.1 Document the date and time at the beginning of the
6.3 Required Apparatus:
test.
6.3.1 Membrane Filter, 47 mm nitro-cellulose, 0.45-µm.
9.1.2 Vigorously mix the sample for 15 s minimum to
6.3.2 Forceps, smooth-tip.
resuspend insolubles uniformly. Visually inspect the inside of
6.3.3 Borosilicate Filter Holder.
thebottleforevidenceofmaterialadherenttothesurfaceofthe
6.3.4 Borosilicate Filtering Flask.
bottle before sampling.
6.3.5 Wash Bottle equipped with 0.22 micron membranes.
6.3.6 Vacuum Source, capable of maintaining a vacuum of
NOTE 2—If adherent material cannot be removed from bottle after
repeated attempts to vigorously mix, include as comment in the reporting
71 kPa 6 5 kPa.
documentation.
6.3.7 Graduated cylinder, 150–200 mL.
9.1.3 Transfer50mL 61mLofsampleintocleanbeakeror
6.3.8 Beaker, 100–250 mL.
6.3.9 Petri dish. Erlenmeyer flask.
6.3.10 Spectrophotometer, with capabilities of analyzing a 9.1.4 Add approximately 50 mL 6 1 mLof petroleum ether
standard 15 mm target with a 0°/45° measuring geometry, 10° to beaker containing sample.
observer, 10 nm spectral intervals minimum resolution, the 9.1.5 Stir sample for approximately 30 s to ensure that a
visible spectral range of 400–700 nm and CIELAB measuring
complete solution (and complete mixing) is attained.
indices.
9.1.6 Pour sample into filter funnel within 1–2 minutes of
initial mixing.
7. Reagents and Materials
9.2 Filtration Process:
7.1 Petroleum Spirit (also known as petroleum ether or IP
9.2.1 Using forceps, mount the filter on the center of the
Petroleum Spirit 40/60) (Warning—Extremely flammable.
filter holder.
Harmful if inhaled. Vapors are easily ignited by electrostatic
9.2.2 Mountandsecurelyclampthefilterfunneltothefilter.
discharges, causing flash fire.), having boiling range from 35 to
9.2.3 Apply a vacuum and ensure a vacuum of less than 76
60°C.
kPa is attained and held.
7.2 Coleman Camp Fuel—Coleman Fuel is a complex
9.2.4 Rinse the beaker twice with a minimum of 35 mL of
mixture of light hydrocarbons (primarily aliphatic) produced
petroleum ether and pour the rinsing into the filter funnel.
by distillation of petroleum. Carbon number range is C5 to C9,
9.2.5 Permit the filtrate to completely flow through.
and contains less than 0.001% benzene.
9.2.6 Carefully, remove the clamp and funnel. Wash any
7.3 Purity of Reagents—Reagent grade chemicals shall be
adhering insolubles from the funnel onto the membrane with
used in all tests. Unless otherwise indicated, it is intended that petroleum ether. Wash the membrane gently, particularly the
all reagents conform to the specifications of the Committee of
edges, with petroleum ether from the wash bottle.
Analytical Reagents of the American Chemical Society where
NOTE 3—If any of the deposits fails to remain on (or falls off) the dry
such specifications are available. Other grades may be used,
membrane the test must be repeated.
provided it is first ascertained that the reagent is of sufficiently
9.2.7 Carefully release the vacuum.
high purity to permit its use without lessening the accuracy of
9.2.8 Remove the clamp and filter holder.
the determination.
9.2.9 Using forceps carefully remove the filter from the
8. Sampling, Test Specimens, and Test Units
filter holder and place into a clean dry petri-dish. To facilitate
handling, the membrane filters might be rested on clean glass
8.1 Using either Practice D4057 (manual sampling) or
rods in the petri-dish.
Practice D4177 (automatic sam
...