ASTM B979-12(2018)

Standard Specification for Non-Specular (NS) Surface Finish on Overhead Aluminum Electrical Conductors

ABSTRACT
This specification covers non-specular surface finishes on overhead aluminum electrical conductors to establish a uniformity of conductor finish that is acceptable to the user. Such a specification will furnish a basis for consistent manufacturing process control. Overhead aluminum electrical conductors, when installed, tend to have a "reflective" or "specular" surface that can make a transmission line more noticeable in appearance against the background landscape. A factory treatment process of the outer surface of the aluminum wires can turn the surface finish into a dull, non-reflective, or "de-glared" matte grey finish that allows the conductor to become less visible when observed from a distance and enables the transmission line to blend in with the skyline or landscape background. This specification addresses ordering information, equipment, test procedure, requirements, and retest.
SCOPE
1.1 This specification covers non-specular surface finishes on overhead aluminum electrical conductors. Overhead aluminum electrical conductors, when installed, typically have a shiny surface appearance. This “reflective” or “specular” surface can make a transmission line more noticeable in appearance against the background landscape. A factory treatment process of the outer surface of the aluminum wires can render the surface finish into a dull, non-reflective, matte grey finish. This non-reflective or “de-glared” surface finish allows the conductor to become less visible when observed from a distance and enables the transmission line to blend in with the skyline or landscape background.2  
1.2 This specification is intended, by means of diffuse reflectance measurement, to establish a uniformity of conductor finish which is acceptable to the user. Such a specification will furnish a basis for consistent manufacturing process control.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

General Information

• Status: Published
• Publication Date: 28-Feb-2018
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.02 - Methods of Test and Sampling Procedure

Relations

• Replaces: ASTM B979-12 - Standard Specification for Non-Specular (NS) Surface Finish on Overhead Aluminum Electrical Conductors
• Effective Date: 01-Mar-2018
• Refers: ASTM B354-16 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 01-Sep-2016
• Refers: ASTM B354-12 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 01-Dec-2012
• Refers: ASTM B354-05 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 01-Mar-2005
• Refers: ASTM B354-98 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 10-Sep-1998

Overview

ASTM B979-12(2018): Standard Specification for Non-Specular (NS) Surface Finish on Overhead Aluminum Electrical Conductors provides requirements and uniform testing methods for non-specular surface treatments on aluminum conductors used in overhead electrical transmission and distribution. These non-specular, or "de-glared," surface finishes reduce the visibility of conductors against the landscape, enhancing their ability to blend with the environment. The specification establishes criteria for ordering, process control, diffuse reflectance measurement, equipment, test procedures, and retesting guidelines, supporting both manufacturer consistency and end-user satisfaction.

Key Topics

• Purpose of Non-Specular Finishes:
  Overhead aluminum electrical conductors are naturally shiny, giving a specular (reflective) appearance that can make transmission lines visually prominent. This standard specifies the requirements for a matte, non-reflective gray finish, termed "non-specular" or "de-glared," which minimizes glare and reflection.
• Uniformity and Quality Control:
  The specification uses diffuse reflectance measurement as the basis for qualifying acceptable surface finish, ensuring product consistency and reliable manufacturing process control.
• Test Procedures and Equipment:
  • Test measurements are performed using a calibrated portable reflectance meter with specific filters.
  • Each production batch undergoes multiple measurements to ensure compliance, with retest procedures clearly outlined should initial results be unsatisfactory.
• Ordering Information:
  The standard clarifies what purchasers must specify, such as the requirement for the NS surface finish and the default maximum diffuse reflectivity value.
• Safety and Regulatory Considerations:
  Users are responsible for applying all relevant safety, health, and environmental practices, as the standard doesn't address these aspects explicitly.

Applications

Non-specular surface finishes on overhead aluminum conductors are widely used in:

• Transmission and distribution lines:
  Utilities and power grid operators utilize non-specular conductors to reduce the visual impact of overhead lines, complying with both regulatory requirements and community aesthetic standards.
• Environmentally sensitive areas:
  In regions where minimizing the visibility of infrastructure is important - such as scenic landscapes, protected natural habitats, or urban zones with strict visual guidelines - NS-finished conductors are preferred.
• Project specifications:
  The standard provides a common reference for engineers, buyers, and manufacturers, streamlining procurement and project documentation related to the external appearance of conductors.

Benefits include:

• Improved visual integration of overhead lines with the environment
• Consistent appearance along long transmission corridors
• Facilitation of regulatory and community acceptance

Related Standards

• ASTM B354 – Terminology Relating to Uninsulated Metallic Electrical Conductors:
  Reference for definitions and terminology relevant to this specification.
• AA/ANSI C7.69 – Aluminum Association Standard:
  Historical basis for the development of this ASTM standard, providing earlier guidance on conductor surface appearance.
• WTO Technical Barriers to Trade (TBT) Committee Principles:
  International recognition of standardization principles, supporting global trade and compliance.

Keywords: non-specular, de-glared, overhead aluminum conductors, matte finish, diffuse reflectance, anti-glare, transmission line aesthetics, ASTM B979

By following ASTM B979-12(2018), manufacturers and users ensure that overhead aluminum electrical conductors meet stringent requirements for non-specular surface finish-improving the aesthetic integration of power lines into a wide range of environments.

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: B979 −12 (Reapproved 2018)
Standard Specification for
Non-Specular (NS) Surface Finish on Overhead Aluminum
Electrical Conductors
This standard is issued under the fixed designation B979; 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 2. Referenced Documents
1.1 This specification covers non-specular surface finishes 2.1 The following documents, in effect on the date of
on overhead aluminum electrical conductors. Overhead alumi- material purchase, form part of this specification to the extent
num electrical conductors, when installed, typically have a referenced herein:
shiny surface appearance. This “reflective” or “specular” 3
2.2 ASTM Standards:
surface can make a transmission line more noticeable in
B354 Terminology Relating to Uninsulated Metallic Electri-
appearance against the background landscape. A factory treat-
cal Conductors
ment process of the outer surface of the aluminum wires can
render the surface finish into a dull, non-reflective, matte grey
3. Terminology
finish. This non-reflective or “de-glared” surface finish allows
3.1 For definitions of terms relating to conductors, refer to
the conductor to become less visible when observed from a
definitions found in Terminology B354.
distance and enables the transmission line to blend in with the
3.2 Definitions:
skyline or landscape background.
3.2.1 specular—a shiny, reflective appearance.
1.2 This specification is intended, by means of diffuse
3.2.2 non-specular—a matte, non-shiny appearance.
reflectance measurement, to establish a uniformity of conduc-
tor finish which is acceptable to the user. Such a specification 3.2.3 de-glared—another term for non-specular.
will furnish a basis for consistent manufacturing process
3.2.4 diffuse reflection—reflection in which light energy is
control.
scattered in many directions by diffusion at or below the
surface.
1.3 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
4. Ordering Information
conversions to SI units that are provided for information only
and are not considered standard. 4.1 Orders for material under this specification shall include
the following information:
1.4 This standard does not purport to address all of the
4.1.1 Aluminum overhead electrical conductor to have a
safety concerns, if any, associated with its use. It is the
non-specular, Type “NS” surface finish.
responsibility of the user of this standard to establish appro-
4.1.2 Unless otherwise specified the default non-specular
priate safety, health, and environmental practices and deter-
grayfinishrequirementshallhaveanaveragemaximumdiffuse
mine the applicability of regulatory limitations prior to use.
reflectivity of not more than 32 %.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Equipment
ization established in the Decision on Principles for the
5.1 To measure diffuse reflectance, a portable reflectance
Development of International Standards, Guides and Recom-
meter shall be employed with search units “Y” or “T,”
mendations issued by the World Trade Organization Technical
equipped with a green tristimulus filter.
Barriers to Trade (TBT) Committee.
1 3
This test method is under the jurisdiction of ASTM Committee B01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Conductors and is the direct responsibility of Subcommittee B01.02 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Methods of Test and Sampling Procedure. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved March 1, 2018. Published March 2018. Originally the ASTM website.
approved in 2012. Last previous edition approved in 2012 as B979 – 12. DOI: Thesolesourceofsupplyoftheapparatus(PhotovoltReflectanceMeter,Model
10.1520/B0979-12R18. No. 577 or 577–A) known to the committee at this time is Photovolt Instruments,
The historical origin of this standard is based upon AA/ANSI Standard C7.69 Inc. If you are aware of alternative suppliers, please provide this information to
originally developed by theAluminumAssociation, Inc. and adopted for recognition ASTM International Headquarters. Your comments will receive careful consider-
as an American National Standard in 1975. ation at a meeting of the responsible technical committee, which you may attend.
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