ASTM D2129-17

Standard Test Method for Color of Clear Electrical <brk/>Insulating Liquids (Platinum-Cobalt Scale)

SIGNIFICANCE AND USE
4.1 Color is significant chiefly as an indicator of contamination in electrical insulating liquids. Frequently this contamination is the result of solvent action in the apparatus involved or it may indicate possible contamination. No definite relationship can be established between color and the physical and electrical characteristics of the liquid; for that reason color in itself has limited value as a measure of condition. For more precise determination of color, Test Method D1209 may be used.
SCOPE
1.1 This standard describes a test method for the visual determination of the color of clear insulating liquids.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3  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.

General Information

• Status: Published
• Publication Date: 31-Dec-2016
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.07 - Physical Test

Relations

• Replaces: ASTM D2129-05(2010) - Standard Test Method for Color of Clear Electrical Insulating Liquids (Platinum-Cobalt Scale)
• Effective Date: 01-Jan-2017
• Refers: ASTM D1500-24 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Mar-2024
• Refers: ASTM D1500-12 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Dec-2012
• Refers: ASTM D1500-07 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Dec-2007
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1209-05e1 - Standard Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)
• Effective Date: 15-May-2005
• Refers: ASTM D1209-05 - Standard Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)
• Effective Date: 15-May-2005
• Refers: ASTM D1500-04a - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Nov-2004
• Refers: ASTM D1500-04 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Jun-2004
• Refers: ASTM D1500-03 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Nov-2003
• Refers: ASTM D1500-02 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 10-Nov-2002
• Refers: ASTM D1209-00 - Standard Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)
• Effective Date: 10-May-2000
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Referred By: ASTM D4652-20 - Standard Specification for Silicone Liquid Used for Electrical Insulation
• Effective Date: 01-Jan-2017

Overview

ASTM D2129-17 - Standard Test Method for Color of Clear Electrical Insulating Liquids (Platinum-Cobalt Scale) - is an internationally recognized method developed by ASTM International. This standard outlines procedures for the visual determination of the color of clear electrical insulating liquids using the platinum-cobalt (Pt-Co) color scale. The color of insulating liquids is a key indicator of potential contamination, which can impact performance in electrical systems.

Color measurement by this standard is significant as an early warning for contamination due to solvent action or external influences. However, it should be noted that no definitive correlation exists between color and other physical or electrical properties of the liquid. For cases needing more precise color measurement, ASTM D1209 is recommended.

Key Topics

• Purpose: Provides a clear, consistent method for visually comparing the color of clear electrical insulating liquids to platinum-cobalt standards.
• Applicability: Ideal for measuring color values within the 5 to 300 Pt-Co range. For higher values, ASTM D1500 should be used.
• Technique: Involves using matched Nessler tubes and a color comparator under controlled lighting to visually assess color intensity.
• Reporting: The result is expressed by the Pt-Co color number that most closely matches the test specimen.
• Limitations:
  • The test is chiefly an indicator of contamination, not a comprehensive measure of oil quality.
  • The method does not specify a relationship between observed color and electrical or physical properties.
  • Users must address all relevant safety and regulatory considerations.

Applications

The ASTM D2129-17 standard method is essential across several industries for:

• Routine Analysis: Power generation, transmission, and transformer servicing industries use this method for regular monitoring of insulating liquids in equipment such as transformers, switchgear, and circuit breakers.
• Quality Control: Manufacturers of electrical insulating liquids employ this standard to ensure product consistency and detect contamination during production.
• Field Testing: Maintenance teams utilize portable color comparators to quickly assess fluid condition in the field, enabling prompt detection of degradation or contamination.
• Laboratory Testing: Accredited laboratories apply this standard when certifying new batches of insulating fluids for compliance and purity.

By identifying changes in color, users gain a practical, timely indication of possible contamination, allowing for preventative maintenance and minimizing equipment failure risks.

Related Standards

To gain a comprehensive understanding of insulating liquid condition, ASTM D2129-17 is often used in conjunction with:

• ASTM D1209 - Test Method for Color of Clear Liquids (Platinum-Cobalt Scale): Offers a more precise method for color determination and can supplement D2129.
• ASTM D1193 - Specification for Reagent Water: Specifies water purity requirements for preparing standards and conducting tests.
• ASTM D1500 - Test Method for ASTM Color of Petroleum Products (ASTM Color Scale): Used when the sample color exceeds 300 Pt-Co units.

Applying these related standards ensures comprehensive evaluation and control over the quality of electrical insulating liquids in various applications.

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Keywords: ASTM D2129-17, color determination, clear electrical insulating liquids, platinum-cobalt color scale, contamination indicator, insulating fluid testing, visual color assessment, laboratory standards.

Standards Content (Sample)

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: D2129 − 17
Standard Test Method for
Color of Clear Electrical
Insulating Liquids (Platinum-Cobalt Scale)
This standard is issued under the fixed designation D2129; 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 of the lower part of the ASTM Color Scale, especially in the
range between 0 and 1.
1.1 This standard describes a test method for the visual
determination of the color of clear insulating liquids.
4. Significance and Use
1.2 The values stated in SI units are to be regarded as
4.1 Color is significant chiefly as an indicator of contami-
standard. No other units of measurement are included in this
standard. nation in electrical insulating liquids. Frequently this contami-
nation is the result of solvent action in the apparatus involved
1.3 This standard does not purport to address all of the
or it may indicate possible contamination. No definite relation-
safety concerns, if any, associated with its use. It is the
ship can be established between color and the physical and
responsibility of the user of this standard to establish appro-
electrical characteristics of the liquid; for that reason color in
priate safety and health practices and determine the applica-
itself has limited value as a measure of condition. For more
bility of regulatory limitations prior to use.
precise determination of color, Test Method D1209 may be
2. Referenced Documents used.
2.1 ASTM Standards:
5. Apparatus
D1193 Specification for Reagent Water
D1209 Test Method for Color of Clear Liquids (Platinum-
5.1 Color Comparison Tubes—Matched, tall-form Nessler
Cobalt Scale)
tubes, graduated at the 50-mL mark, and provided with
D1500 Test Method forASTM Color of Petroleum Products
ground-on, optically clear glass caps.
(ASTM Color Scale)
5.2 Color Comparator—A color comparator constructed to
3. Summary of Test Method permit visual comparison of light transmitted through tall-form
Nessler tubes in the direction of their longitudinal axes. The
3.1 The color determined by this test method is derived by
comparator should be constructed so that white light is passed
comparing the color of the test specimen with that of a series
through or reflected off a white glass plate and directed with
of numbered color reference standards using transmitted light
equal intensity through the tubes, and should be shielded so
under prescribed conditions. The procedure described is based
that no light enters the tubes from the side. Alternatively, a
on that for measuring the color of water and clear liquids
color comparator that uses glass color standards and Nessler
according to the platinum-cobalt scale. This scale is suitable
tubes that conforms to Test Method D1209 can be used.
formeasurementsoverthecolorrangefrom5to300.Thecolor
of test specimens darker than 300 on the platinum-cobalt scale
6. Reagents
must be measured according to the ASTM Color Scale as
described in Test Method D1500. The use of the platinum-
6.1 Purity of Reagents—Use reagent grade chemicals in all
cobalt scale in this way is primarily of value as an expansion
tests. Unless otherwise indicated, all reagents will conform to
the specifications of the Committee on Analytical Reagents of
the American Chemical Society, where such specifications are
This test method is under the jurisdiction of ASTM Committee on D27 on
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
mittee D27.07 on Physical Test.
Current edition approved Jan. 1, 2017. Published February 2017. Originally
approved in 1962 as D2129 - 62 T. Last previous edition approved in 2010 as Thesolesourceofsupplyofaunitthathasbeenfoundsuitableforthispurpose,
D2129 - 05(2010). DOI: 10.1520/D2129-17. known to the committee at this time is Scientific Glass and Instruments, Inc. P.O.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Box 6, Houston,TX 77001. If you are aware of alternative suppliers, please provide
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM this information to ASTM International Headquarters. Your comments will receive
Standards volume information, refer to the standard’s Document Summary page on careful consideration at a meeting of the responsible technical committee, which
the ASTM website. you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2129 − 17
available. Other grades may be used, provided it is first diluting the required volumes to 50 mL with water in the
ascertained that the reagent is of sufficiently high purity to Nessler tubes. Cap the tubes and seal the caps with shellac or
permit its use without lessening the accuracy of the determi- a waterproof cement.
nation.
8. Procedure
6.2 Purity of Water—Use reagent water conforming to
8.1 Introduce 50 mL of the test specimen into a Nessler
Specification D1193.
tube,passingthesamplethroughafilterifithasanyvisibletest
6.3 Solvent, suitable, clear.
specimen turbidity. Cap the tube, place in the comparator, and
compare with the standards.
6.4 Cobaltous Chloride (CoCl ·6H O).
2 2
8.2 If th
...

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. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D2129 − 05 (Reapproved 2010) D2129 − 17
Standard Test Method for
Color of Clear Electrical
Insulating Liquids (Platinum-Cobalt Scale)
This standard is issued under the fixed designation D2129; 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
1.1 This standard describes a test method for the visual determination of the color of clear insulating liquids.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
3. Summary of Test Method
3.1 The color determined by this test method is derived by comparing the color of the test specimen with that of a series of
numbered color reference standards using transmitted light under prescribed conditions. The procedure described is based on that
for measuring the color of water and clear liquids according to the platinum-cobalt scale. This scale is suitable for measurements
over the color range from 5 to 300. The color of test specimens darker than 300 on the platinum-cobalt scale must be measured
according to the ASTM Color Scale as described in Test Method D1500. The use of the platinum-cobalt scale in this way is
primarily of value as an expansion of the lower part of the ASTM Color Scale, especially in the range between 0 and 1.
4. Significance and Use
4.1 Color is significant chiefly as an indicator of contamination in electrical insulating liquids. Frequently this contamination
is the result of solvent action in the apparatus involved or it may indicate possible contamination. No definite relationship can be
established between color and the physical and electrical characteristics of the liquid; for that reason color in itself has limited value
as a measure of condition. For more precise determination of color, Test Method D1209 may be used.
5. Apparatus
5.1 Color Comparison Tubes—Matched, tall-form Nessler tubes, graduated at the 50-mL mark, and provided with ground-on,
optically clear glass caps.
5.2 Color Comparator—A color comparator constructed to permit visual comparison of light transmitted through tall-form
Nessler tubes in the direction of their longitudinal axes. The comparator should be constructed so that white light is passed through
This test method is under the jurisdiction of ASTM Committee on D27 on Electrical Insulating Liquids and Gases and is the direct responsibility of Subcommittee D27.07
on Physical Test.
Current edition approved Nov. 1, 2010Jan. 1, 2017. Published November 2010February 2017. Originally approved in 1962 as D2129 - 62 T. Last previous edition approved
in 20052010 as D2129 - 05.D2129 - 05(2010). DOI: 10.1520/D2129-05R10.10.1520/D2129-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2129 − 17
or reflected off a white glass plate and directed with equal intensity through the tubes, and should be shielded so that no light enters
the tubes from the side. Alternatively, a color comparator that uses glass color standards and Nessler tubes that conforms to Test
Method D1209 can be used.
6. Reagents
6.1 Purity of Reagents—Use reagent grade chemicals in all tests. Unless otherwise indicated, all reagents will conform to the
specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are
available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use
without lessening the accuracy of the determination.
6.2 Purity of Water—Use reagent water conforming to Specification D1193.
6.3 Solvent, suitable, clear.
6.4 Cobaltous Chloride (CoCl ·6H O).
2 2
6.5 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
6.6 Potassium Chloroplatinate (K PtCl ).
2 6
7. Preparation of Color Standards
7.1 Platinum-Cobalt Stock Solution—Dissolve 1.245 g of K PtCl (containing 0.5 g of platinum) and 1.000 g of CoCl ·6H O
2 6 2 2
(containing about 0.25 g of cobalt) in water. Add 100 mL of HCl (sp gr 1.19) and dilute to 1 L with water. This solution has a color
of 500.
NOTE 1—The color standard stock solution (platinum-cobalt solution) can be purchased with a color of 500 from laboratory supply firms.
7.2 Platinum-Cobalt Standards —The unit of color is that color produced by 1 mg of platinum per litre. From the stock solution,
prepare color standards, as given in Table 1, by diluting the required volum
...