ASTM D7843-21

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.
Designation: D7843 − 21
Standard Test Method for
Measurement of Lubricant Generated Insoluble Color
Bodies in In-Service Turbine Oils using Membrane Patch
1
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* D4898 Test Method for Insoluble Contamination of Hydrau-
lic Fluids by Gravimetric Analysis
1.1 This test method extracts insoluble contaminants from a
D5452 Test Method for Particulate Contamination in Avia-
sample of in-service turbine oil onto a patch and the color of
tion Fuels by Laboratory Filtration
the membrane patch is analyzed by a spectrophotometer. The
D7317 Test Method for Coagulated Pentane Insolubles in
results are reported as a ∆E value, within the CIELAB scale.
Used Lubricating Oils by Paper Filtration (LMOA
1.2 This test method is not appropriate for turbine oils with
Method)
dyes.
E177 Practice for Use of the Terms Precision and Bias in
1.3 The values stated in SI units are to be regarded as ASTM Test Methods
E284 Terminology of Appearance
standard. No other units of measurement are included in this
standard. E308 PracticeforComputingtheColorsofObjectsbyUsing
the CIE System
1.4 This standard does not purport to address all of the
E691 Practice for Conducting an Interlaboratory Study to
safety concerns, if any, associated with its use. It is the
Determine the Precision of a Test Method
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions:
1.5 This international standard was developed in accor-
3.1.1 CIELAB color scales, n—CIE 1976 L*, a*, b*
dance with internationally recognized principles on standard-
opponent-color scales, in which a* is positive in the red
ization established in the Decision on Principles for the
direction and negative in the green direction; b* is positive in
Development of International Standards, Guides and Recom-
the yellow direction and negative in the blue direction; and L*
mendations issued by the World Trade Organization Technical
is positive in the lightness direction and negative in the
Barriers to Trade (TBT) Committee.
darkness direction. E308
2. Referenced Documents 3.1.2 colorimetry, n—the science of color measurement.
2 E284
2.1 ASTM Standards:
3.1.3 in-service oil, n—lubricating oil that is present in a
D4057 Practice for Manual Sampling of Petroleum and
machine that has been at operating temperature for at least one
Petroleum Products
hour.
D4177 Practice for Automatic Sampling of Petroleum and
Petroleum Products
3.1.4 membrane color, n—a visual rating of particulate on a
D4378 Practice for In-Service Monitoring of Mineral Tur-
filter membrane against ASTM Color Standards.
bine Oils for Steam, Gas, and Combined Cycle Turbines
3.1.5 membrane filter, n—a porous article of closely con-
trolled pore size through which a liquid is passed to separate
matter in suspension.
1
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of 3.2 Definitions of Terms Specific to This Standard:
Subcommittee D02.C0.01 on Turbine Oil Monitoring, Problems and Systems.
3.2.1 soot, n—in internal combustion engines, sub-micron
Current edition approved April 1, 2021. Published April 2021. Originally
size particles, primarily carbon, created in the combustion
approved in 2012. Last previous edition approved in 2018 as D7843 – 18. DOI:
chamber as products of incomplete combustion.
10.1520/D7843-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.2.2 varnish, n—a thin, hard, lustrous, oil-insoluble
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
deposit, composed primarily of organic residue, and most
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. readily definable by color intensity. It is not easily removed by
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7843 − 21
3
wiping with a clean, dry, soft, lint-free wiping material and is Analytical Reagents of theAmerican Chemical Society where
r
...