ASTM D1711-24

Standard Terminology Relating to Electrical Insulation

SCOPE
1.1 This terminology standard is a compilation of technical terms associated with testing and specifying solid electrical and electronic insulating materials.  
1.2 This terminology standard shall contain all definitions that are balloted specifically through Subcommittee D09.94 and through D09 main committee and that are of general interest to standards associated with electrical and electronic insulating materials. Those definitions shall be of importance to electrical and electronic insulating materials issues but need not be directly associated with a specific standard under the jurisdiction of Committee D09 on Electrical and Electronic Insulating Materials.  
1.3 It is intended that all definitions in this terminology standard originating in a specific standard under the jurisdiction of Committee D09 be identical to definitions of the same terms as printed in standards of originating technical subcommittees, with the exceptions of: (1) deletion of any part of the Discussion included in another standard that refers specifically to the use of a term in that standard; (2) figure numbers and corresponding references; and (3) in this terminology standard, a parenthetical addition of a reference to one or more technical standards in which the term is used and the year in which the term was added to this compilation.  
1.3.1 Definitions contained in this terminology standard which did not originate in a specific standard under the jurisdiction of Committee D09, or which originated in a standard that has since been revised or withdrawn, and that have been appropriately balloted, shall also be included in this terminology standard.  
1.4 It is permissible to include symbols as part of the representation of terms, where appropriate.  
1.5 It is not intended that this terminology standard include symbols (except as noted in 1.4). It is also permissible to include acronyms and abbreviations referring directly to defined terms.  
1.6 Revisions and additions to those definitions in this terminology standard which originate in a specific standard under the jurisdiction of Committee D09 are to be made as a product of a collaborative effort between Subcommittee D09.94 and the corresponding technical subcommittee of Committee D09, with Subcommittee D09.94 providing editorial advice to the technical subcommittees.  
1.7 Each definition in this terminology standard shall be accompanied by the year in which it was first incorporated into the standard, placed at the end in parentheses. All discussions shall also carry a date; it is possible that the discussion date is different from the definition date.  
1.8 1.8.1 – 1.8.3 contain references to specific terminology standards that are relevant to specific electrical insulating materials or applications. In case of conflict between a definition contained in Terminology D1711 and one contained in another standard, the definition given in Terminology D1711 shall prevail.  
1.8.1 For terms related to plastics, the applicable definitions are contained in Terminology D883.  
1.8.2 For terms relating to fire, the applicable definitions are contained in Terminology E176 and ISO 13943. In case of conflict between Terminology E176 and ISO 13943, the definitions given in Terminology E176 shall prevail.  
1.8.3 For terms relating to precision and bias and associated issues, the applicable definitions are contained in Terminology E456.  
1.9 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: 29-Feb-2024
• ICS: 01.040.29 - Electrical engineering (Vocabularies)
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.94 - Editorial

Relations

• Replaces: ASTM D1711-22 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Mar-2024
• Refers: ASTM D3353-18(2024) - Standard Test Methods for Fibrous-Insulated Magnet Wire
• Effective Date: 01-Mar-2024
• Refers: ASTM D1830-17(2024) - Standard Test Method for Thermal Endurance of Flexible Sheet Materials Used for Electrical Insulation by the Curved Electrode Method
• Effective Date: 01-Mar-2024
• Refers: ASTM D115-17(2024) - Standard Test Methods for Testing Solvent Containing Varnishes Used for Electrical Insulation
• Effective Date: 01-Mar-2024
• Refers: ASTM E456-13a(2022) - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM E456-13a(2022)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM D1830-17 - Standard Test Method for Thermal Endurance of Flexible Sheet Materials Used for Electrical Insulation by the Curved Electrode Method
• Effective Date: 01-Nov-2017
• Refers: ASTM D115-17 - Standard Test Methods for Testing Solvent Containing Varnishes Used for Electrical Insulation
• Effective Date: 01-Nov-2017
• Referred By: ASTM D4245-21 - Standard Specification for Ozone-Resistant Thermoplastic Elastomer Insulation For Wire and Cable, 90 °C Dry/75 °C Wet Operation
• Effective Date: 01-Mar-2024
• Referred By: ASTM D5642-16(2022) - Standard Test Method for Sealed Tube Chemical Compatibility Test
• Effective Date: 01-Mar-2024
• Referred By: ASTM D3555-20e1 - Standard Specification for Track-Resistant Crosslinked Polyethylene Insulation for Wire and Cable, 90 °C Operation
• Effective Date: 01-Mar-2024
• Referred By: ASTM D3755-20 - Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials Under Direct-Voltage Stress
• Effective Date: 01-Mar-2024
• Referred By: ASTM D4246-14(2020) - Standard Specification for Ozone-Resistant Thermoplastic Elastomer Insulation for Wire and Cable, 90 °C Operation
• Effective Date: 01-Mar-2024
• Referred By: ASTM D4313-22 - Standard Specification for General-Purpose, Heavy-Duty, and Extra-Heavy-Duty Crosslinked Chlorinated Polyethylene (CPE) Jackets For Wire and Cable
• Effective Date: 01-Mar-2024
• Referred By: ASTM D3353-18 - Standard Test Methods for Fibrous-Insulated Magnet Wire
• Effective Date: 01-Mar-2024

Overview

ASTM D1711-24: Standard Terminology Relating to Electrical Insulation provides a comprehensive compilation of technical terms used in the testing and specification of solid electrical and electronic insulating materials. Developed by ASTM Committee D09 and its subcommittees, this terminology standard supports consistent language across standards and documents involving electrical and electronic insulating materials. The standard covers terms relevant to a broad range of insulation topics including materials such as electrical insulating papers, mica, processed mica forms, hookup wire insulation, and partial discharge (corona).

Clear and harmonized terminology is vital for manufacturers, testing laboratories, and users to ensure accurate communication, facilitate product compliance, and promote international trade in electrical insulation materials.

Key Topics

• Definitions and Terms: The standard provides precise definitions that have been balloted through ASTM Subcommittee D09.94 or the main Committee D09. These terms are selected for their broad relevance across standards for electrical and electronic insulating materials.
• Integration with Other Standards: Terms originating from specific ASTM standards under Committee D09 are harmonized for consistency, with references to associated standards and the date of inclusion.
• Scope of Coverage: The terminology addresses general applications, as well as specialized materials and processes, such as:
  • Electrical insulating papers
  • Mica and its processing
  • Magnet wire enamels and insulation
  • Partial discharge (corona)
  • Adhesive and encapsulation terminology
• Inclusion of Symbols and Abbreviations: Where suitable, symbols, acronyms, and abbreviations are included as part of term definitions to promote clarity.
• International Harmonization: The standard observes internationally recognized principles and aligns with World Trade Organization (WTO) guidelines for the development of international standards.

Applications

ASTM D1711-24 serves as a foundational reference for a variety of professionals and organizations involved with electrical insulation:

• Manufacturers of Insulating Materials: Use the standard to ensure clear product specifications and meet international compliance for wire, cable, varnishes, enamels, tapes, papers, and composite insulation products.
• Testing Laboratories: Reference standardized terms during evaluation of dielectric performance, breakdown voltage, insulation resistance, and other material properties.
• Product Designers and Engineers: Rely on consistent technical language when specifying materials for use in transformers, motors, generators, cable assemblies, and other electrical apparatus.
• Regulatory and Certification Bodies: Employ the standardized definitions to assess conformance with safety and quality standards in regulatory applications.
• Technical Writers and Standards Developers: Utilize the unified terminology when drafting test methods, practices, or specifications to ensure cross-standard consistency and to clarify discussions in material or performance requirements.

Related Standards

ASTM D1711-24 is closely connected with several other ASTM and international standards to ensure holistic coverage of terminology across material types and applications. Notable related standards include:

• ASTM D883: Terminology Relating to Plastics - applicable for terms specific to polymeric insulating materials.
• ASTM E176: Terminology of Fire Standards - referenced for fire-related insulation terminology; supersedes ISO 13943 in case of discrepancies.
• ASTM E456: Terminology Relating to Quality and Statistics - covers precision and bias concepts relevant to insulation testing.
• ISO 13943: Fire Safety - Vocabulary - for international coverage of fire safety terms.
• Referenced Test Methods: Includes D149 (Dielectric Breakdown Voltage), D150 (Permittivity), D257 (DC Resistance or Conductance), D470 (Insulations and Jackets), D1000 (Adhesive-Coated Tapes), among others.

For more detail and the full list of referenced documents, consult the ASTM D1711-24 standard and related standards through the ASTM International platform.

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Keywords: ASTM D1711-24, electrical insulation terminology, insulating materials, dielectric strength, partial discharge, electrical tests, standard definitions, ASTM standards, insulating papers, mica insulation, wire insulation

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: D1711 − 24
Standard Terminology Relating to
Electrical Insulation
This standard is issued under the fixed designation D1711; 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.
INTRODUCTION
This terminology is used in connection with testing and specifying solid electrical insulating
materials. Modifications to this terminology, reflecting common usage, may appear in particular test
methods, material specifications, practices, or other standards. Included herein are terms pertinent to
general applications, electrical insulating papers, mica, mica processing, processed mica forms,
hookup wire insulation, and partial discharge (corona).
1. Scope* have been appropriately balloted, shall also be included in this
terminology standard.
1.1 This terminology standard is a compilation of technical
1.4 It is permissible to include symbols as part of the
terms associated with testing and specifying solid electrical and
representation of terms, where appropriate.
electronic insulating materials.
1.5 It is not intended that this terminology standard include
1.2 This terminology standard shall contain all definitions
symbols (except as noted in 1.4). It is also permissible to
that are balloted specifically through Subcommittee D09.94
include acronyms and abbreviations referring directly to de-
and through D09 main committee and that are of general
fined terms.
interest to standards associated with electrical and electronic
insulating materials. Those definitions shall be of importance
1.6 Revisions and additions to those definitions in this
to electrical and electronic insulating materials issues but need
terminology standard which originate in a specific standard
not be directly associated with a specific standard under the
under the jurisdiction of Committee D09 are to be made as a
jurisdiction of Committee D09 on Electrical and Electronic
product of a collaborative effort between Subcommittee
Insulating Materials.
D09.94 and the corresponding technical subcommittee of
Committee D09, with Subcommittee D09.94 providing edito-
1.3 It is intended that all definitions in this terminology
rial advice to the technical subcommittees.
standard originating in a specific standard under the jurisdic-
tion of Committee D09 be identical to definitions of the same
1.7 Each definition in this terminology standard shall be
terms as printed in standards of originating technical accompanied by the year in which it was first incorporated into
subcommittees, with the exceptions of: (1) deletion of any part
the standard, placed at the end in parentheses. All discussions
of the Discussion included in another standard that refers shall also carry a date; it is possible that the discussion date is
specifically to the use of a term in that standard; (2) figure
different from the definition date.
numbers and corresponding references; and (3) in this termi-
1.8 1.8.1 – 1.8.3 contain references to specific terminology
nology standard, a parenthetical addition of a reference to one
standards that are relevant to specific electrical insulating
or more technical standards in which the term is used and the
materials or applications. In case of conflict between a defini-
year in which the term was added to this compilation.
tion contained in Terminology D1711 and one contained in
1.3.1 Definitions contained in this terminology standard
another standard, the definition given in Terminology D1711
which did not originate in a specific standard under the
shall prevail.
jurisdiction of Committee D09, or which originated in a
1.8.1 For terms related to plastics, the applicable definitions
standard that has since been revised or withdrawn, and that
are contained in Terminology D883.
1.8.2 For terms relating to fire, the applicable definitions are
contained in Terminology E176 and ISO 13943. In case of
conflict between Terminology E176 and ISO 13943, the
This terminology is under the jurisdiction of ASTM Committee D09 on
Electrical and Electronic Insulating Materials and is the direct responsibility of
definitions given in Terminology E176 shall prevail.
Subcommittee D09.94 on Editorial.
1.8.3 For terms relating to precision and bias and associated
Current edition approved March 1, 2024. Published March 2024. Originally
issues, the applicable definitions are contained in Terminology
approved in 1960. Last previous edition approved in 2022 as D1711 – 22. DOI:
10.1520/D1711-24. E456.
*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
D1711 − 24
1.9 This international standard was developed in accor- ings Used for Electrical Insulation (Withdrawn 2002)
dance with internationally recognized principles on standard- D3288/D3288M Test Methods for Magnet-Wire Enamels
ization established in the Decision on Principles for the
D3312 Test Method for Percent Reactive Monomer in Sol-
Development of International Standards, Guides and Recom-
ventless Varnishes
mendations issued by the World Trade Organization Technical
D3353 Test Methods for Fibrous-Insulated Magnet Wire
Barriers to Trade (TBT) Committee.
D3382 Test Methods for Measurement of Energy and Inte-
grated Charge Transfer Due to Partial Discharges (Co-
2. Referenced Documents
rona) Using Bridge Techniques
2.1 ASTM Standards:
D3426 Test Method for Dielectric Breakdown Voltage and
D115 Test Methods for Testing Solvent Containing Var-
Dielectric Strength of Solid Electrical Insulating Materials
nishes Used for Electrical Insulation
Using Impulse Waves
D149 Test Method for Dielectric Breakdown Voltage and
D3636 Practice for Sampling and Judging Quality of Solid
Dielectric Strength of Solid Electrical Insulating Materials
Electrical Insulating Materials
at Commercial Power Frequencies
D3755 Test Method for Dielectric Breakdown Voltage and
D150 Test Methods for AC Loss Characteristics and Permit-
Dielectric Strength of Solid Electrical Insulating Materials
tivity (Dielectric Constant) of Solid Electrical Insulation
Under Direct-Voltage Stress
D176 Test Methods for Solid Filling and Treating Com-
3 D4313 Specification for General-Purpose, Heavy-Duty, and
pounds Used for Electrical Insulation (Withdrawn 2013)
Extra-Heavy-Duty Crosslinked Chlorinated Polyethylene
D202 Test Methods for Sampling and Testing Untreated
(CPE) Jackets For Wire and Cable
Paper Used for Electrical Insulation
D4323 Test Method for Hydrogen Sulfide in the Atmosphere
D257 Test Methods for DC Resistance or Conductance of
by Rate of Change of Reflectance
Insulating Materials
D4470 Test Method for Static Electrification
D470 Test Methods for Crosslinked Insulations and Jackets
D4496 Test Method for D-C Resistance or Conductance of
for Wire and Cable
Moderately Conductive Materials
D883 Terminology Relating to Plastics
D1000 Test Methods for Pressure-Sensitive Adhesive- D4733 Test Methods for Solventless Electrical Insulating
Coated Tapes Used for Electrical and Electronic Applica- Varnishes
tions
D4880 Test Method for Salt Water Proofness of Insulating
D1676 Test Methods for Film-Insulated Magnet Wire
Varnishes Over Enamelled Magnet Wire
D1830 Test Method for Thermal Endurance of Flexible
D4881 Test Method for Thermal Endurance of Varnished
Sheet Materials Used for Electrical Insulation by the
Fibrous- or Film-Wrapped Magnet Wire
Curved Electrode Method
D4882 Test Method for Bond Strength of Electrical Insulat-
D1868 Test Method for Detection and Measurement of
ing Varnishes by the Twisted-Coil Test
Partial Discharge (Corona) Pulses in Evaluation of Insu-
D5288 Test Method for Determining Tracking Index of
lation Systems
Electrical Insulating Materials Using Various Electrode
D2303 Test Methods for Liquid-Contaminant, Inclined-
Materials (Excluding Platinum)
Plane Tracking and Erosion of Insulating Materials
D6053 Test Method for Determination of Volatile Organic
D2304 Test Method for Thermal Endurance of Rigid Elec-
Compound (VOC) Content of Electrical Insulating Var-
trical Insulating Materials
nishes
D2307 Test Method for Thermal Endurance of Film-
E176 Terminology of Fire Standards
Insulated Round Magnet Wire
E456 Terminology Relating to Quality and Statistics
D2519 Test Method for Bond Strength of Electrical Insulat-
ing Varnishes by the Helical Coil Test
2.2 Other Standards:
D2671 Test Methods for Heat-Shrinkable Tubing for Elec- ANSI/ASQC A2-1987 Terms, Symbols, and Definitions for
4, 5
trical Use
Acceptance Sampling
D2967 Test Method for Corner Coverage of Powder Coat-
GB/T 26667 Terminology for Electromagnetic Shielding
ings
Materials
D3032 Test Methods for Hookup Wire Insulation
ISO 13943 Fire Safety-Vocabulary
D3056 Test Method for Gel Time of Solventless Varnishes
D3145 Test Method for Thermal Endurance of Electrical
Insulating Varnishes by Helical Coil Method
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
D3214 Test Methods for Coating Powders and Their Coat-
4th Floor, New York, NY 10036, http://www.ansi.org.
ASQC A2 has been superseded and replaced by ASQC 3534-2, published by
the American Society for Quality, 600 North Plankinton Road, PO Box 3005,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Milwaukee, WI 53201 United States, www.asq.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from Standardization Administration of China, Haidian District,
Standards volume information, refer to the standard’s Document Summary page on Beijing, People’s Republic of China.
the ASTM website. Available from International Organization for Standardization (ISO), ISO
The last approved version of this historical standard is referenced on Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
www.astm.org. Switzerland, https://www.iso.org.
D1711 − 24
3. Terminology braid, n—(1) woven metallic wire used as a shield for
insulated conductors and cables.
absorbing material, n—material capable of absorbing energy
(2) A woven fibrous protective outer covering over an
from an electromagnetic wave. (2014)
insulated conductor or cable. (2011)
acceptable quality level (AQL), n—the maximum percent
breakdown voltage—see dielectric breakdown voltage.
nonconforming which, for purposes of sampling inspection,
bursting strength of paper, n—the hydrostatic pressure re-
is considered satisfactory as a process average. (2011)
quired to produce rupture of a circular area of the material
D3636
under specified test conditions. (1996) D202
acceptance number, n—the maximum allowable number of
cable wrap, n—paper used for mechanical protection or for
nonconformities for a given AQL and sample size (lot-
space-filling (rather than as electrical insulation) in low-
sample size). (2011) D3636
voltage cables with nonmetallic sheaths. (2011)
aging (act of), n—exposure of material to air or oil at a
capacitance, C, n—that property of a system of conductors and
temperature and time as specified in the relevant material
dielectrics which permits the storage of electrically separated
specification for that material. (2013) D470, D4313, D4323
charges when potential differences exist between the con-
air chain, n—in mica, a series of air inclusions in the form of
ductors. (2011)
a chain or streak. (2011)
DISCUSSION—Capacitance is the ratio of a quantity, q, of electricity to
a potential difference, V. A capacitance value is always positive. The
arc propagation, n—the movement of an electric arc from its
units are farads when the charge is expressed in coulombs and the
point of inception to another location. (1996) D3032
potential in volts (2011):
arc tracking, n—the process producing tracks when arcs occur
C 5 q/V (2)
on or close to the insulation surface. (2011)
D150
Arrhenius plot, n—a graph of the logarithm of thermal life as
capacitor tissue, n—very thin (5 to 50 μm) pure, nonporous
a function of the reciprocal of absolute temperature. (2011)
paper used as the dielectric in capacitors, usually in conjunc-
DISCUSSION—This is normally depicted as the best straight line fit,
tion with an insulating liquid. (2011)
determined by least squares, of end points obtained at aging tempera-
tures. It is important that the slope, which is the activation energy of the
coating powder, n—a heat-fusible, finely-divided solid resin-
degradation reaction, be approximately constant within the selected
ous material used to form electrical insulating coatings.
temperature range to ensure a valid extrapolation. (2011) D2304
(1996) D2967, D3214
ash content of paper, n—the solid residue remaining after
concentricity, n—the ratio, expressed in percent, of the mini-
combustion of the paper under specified conditions, ex-
mum wall thickness to the maximum wall thickness. (2011)
pressed as a percentage of the dry mass of the original paper.
D2671
(1996) D202
concentric-lay conductor, n—a conductor composed of a
average discharge (corona) current (I ), n—the sum of the
t
central core surrounded by one or more layers of helically
absolute magnitudes of the individual discharges during a
laid strands. (2011)
certain time interval divided by that time interval. (2011)
DISCUSSION—In the most common type of concentric-lay conductor,
DISCUSSION—When the discharges are measured in coulombs and the
all strands are of the same size and the central core is a single
time interval in seconds, the calculated current will be in am-
strand. (2011)
peres. (2011)
t
conductance, insulation, n—the ratio of the total volume and
Q 1Q 1222222Q
( 1 2 n
surface current between two electrodes (on or in a specimen)
t
I 5 (1)
t
t 2 t to the dc voltage applied to the two electrodes. (2011)
1 0
DISCUSSION—Insulation conductance is the reciprocal of insulation
where:
resistance. (2011) D257
I = average current, A,
t
t = starting time, s, conductance, surface, n—the ratio of the current between two
t = completion time, s, and
electrodes (on the surface of a specimen) to the dc voltage
Q , Q , Q = partial discharge quantity in a corona pulse 1
applied to the electrodes. (2011)
1 2 n
through n, C.
DISCUSSION—(Some volume conductance is unavoidably included in
D1868
the actual measurement.) Surface conductance is the reciprocal of
surface resistance. (2011) D257
binder tape—see core wrap (binder tape).
bond strength, n—a measure of the force required to separate
conductance, volume, n—the ratio of the current in the
surfaces which have been bonded together. (1996)
volume of a specimen between two electrodes (on or in the
D2519, D3145, D4882
specimen) to the dc voltage applied to the two elec-
trodes. (2011)
DISCUSSION—Volume conductance is the reciprocal of volume resis-
This term is defined in a way similar to the way it appears in the GB/T 26667
standard entitled, “Terminology for Electromagnetic Shielding Materials.” tance. (2011) D257
D1711 − 24
coincide, being either more or less stringent. More stringent sampling
conducting material (conductor), n—a material within which
(for example, smaller AQL values) is usually used for measurement of
an electric current is produced by application of a voltage
characteristics which are considered critical. The selection of sampling
between points on, or within, the material. (2011)
plans is independent of whether the term defect or nonconformity is
DISCUSSION—The term “conducting material” is usually applied only
appropriate. (2011) D3636
to those materials in which a relatively small potential difference results
in a relatively large current since all materials appear to permit some
cross grains or reeves, n—in mica, tangled laminations
conduction current. Metals and strong electrolytes are examples of
causing imperfect cleavage. (2011)
conducting materials. (2011) D4470
crude mica—mica as mined; crude crystals with dirt and rock
conductive fiber, n—fiber which is a conductive material or is
adhering. (2011)
otherwise made conductive on the surface. (2014)
conductive gasket, n—conductive material used at a joint to crystallographic discoloration, n—in mica, discoloration ap-
pearing as bands of lighter or darker shades of basic color of
ensure effective conductive contact. (2014)
a block of mica. (1996)
conductivity, surface, n—the surface conductance multiplied
DISCUSSION—Such bands are generally parallel to the crystallo-
by that ratio of specimen surface dimensions (distance
graphic faces of the crystal from which the block was separated. (2011)
between electrodes divided by the width of electrodes
defining the current path) which transforms the measured defect, n—a departure of a quality characteristic from its
conductance to that obtained if the electrodes had formed the intended level, or state, that occurs with a severity sufficient
opposite sides of a square. (2011) to cause an associated product or service not to satisfy
DISCUSSION—Surface conductivity is expressed in siemens. It is
intended normal, or reasonably foreseeable, usage require-
popularly expressed as siemens/square (the size of the square is
ments. (2011)
immaterial). Surface conductivity is the reciprocal of surface resistiv-
DISCUSSION—The terms “defect” and “nonconformity” and their
ity. (2011) D257
derivatives are used somewhat interchangeably in the historical and
current literature. Nonconformity objectively describes the comparison
conductivity, volume, n—the volume conductance multiplied
of test results to specification requirements, while the term defect has a
by that ratio of specimen volume dimensions (distance
connotation of predicting the failure of a product or service to perform
between electrodes divided by the cross-sectional area of the
its intended function in use. Since this latter connotation is often
electrodes) which transforms the measured conductance to
unintended, the term nonconformity is preferred in full consensus
that conductance obtained if the electrodes had formed the standards. The selection of any sample plan is independent of whether
the term defect or nonconformity is appropriate.
opposite sides of a unit cube. (2011)
The term defect may be appropriate for specifications mutually
DISCUSSION—Volume conductivity is usually expressed in siemens/
agreed upon by a producer and a user where specific use conditions are
centimetre or in siemens/metre and is the reciprocal of volume
clearly understood. Even in these cases however, use the term defect
resistivity. (2011) D257
with caution and consider substituting the term nonconformity.
conductor, n—a wire, or combination of wires not insulated For additional comments, see ANSI/ASQC A2-1987 that also states:
“When a quality characteristic of a product or service is “evaluated” in
from each other, suitable for carrying electric current. (1996)
terms of conformance to specification requirements, the use of the term
D1676
nonconformity is appropriate.” (2011) D3636
continuous partial discharges (continuous corona),
dielectric, n—a medium in which it is possible to maintain an
n—discharges that recur at rather regular intervals; for
electric field with little supply of energy from outside
example on approximately every cycle of an alternating
sources. (2011)
voltage or at least once per minute for an applied direct
DISCUSSION—The energy required to produce the electric field is
voltage. (2011) D1868
recoverable, in whole or in part. A vacuum, as well as any insulating
core wrap (binder tape), n—paper used to wrap groups of
material, is a dielectric. (2011)
insulated wire into cable configuration prior to sheath-
dielectric breakdown voltage (electric breakdown voltage),
ing. (2011)
n—the potential difference at which dielectric failure occurs
DISCUSSION—Usually, this term is applied to telephone communica-
under prescribed conditions, in an electrical insulating ma-
tion cables in which core wrap is not regularly subjected to voltage
stress, but may be exposed to surges from lightning strokes or other terial located between two electrodes. (See also Test Method
accidental events. (2011)
D149, Appendix X1.) (2011)
DISCUSSION—The term dielectric breakdown voltage is sometimes
corona, n—visible partial discharges in gases adjacent to a
shortened to “breakdown voltage.” (2011) D149
conductor. (2011)
DISCUSSION—This term has also been used to refer to partial
dielectric constant—see relative permittivity.
discharges in general. (2011) D1868
dielectric failure (under test), n—an event that is evidenced
critical property, n—a quantitatively measurable characteris-
by an increase in conductance in the dielectric under test
tic which is absolutely necessary to be met if a material or
limiting the electric field that can be sustained. (2011) D149
product is to provide satisfactory performance for the
dielectric strength, n—the voltage gradient at which dielectric
intended use. (2011)
failure of the insulating material occurs under specific
DISCUSSION—In some situations, specification requirements coincide
with customer usage requirements. In other situations, they may not conditions of test. (2011) D149, D176, D3755
D1711 − 24
dip encapsulation (a type of conformal coating), n—an
embedding process in which the insulating material is
applied by immersion and without the use of an outer
container. (2011)
DISCUSSION—The coating so formed generally conforms with the
contour of the embedded part. (2011)
dissipation factor (loss tangent) (tan δ), D, n—the ratio of the
loss index to its relative permittivity or
D 5 κ"/κ' (3)
It is also the tangent of its loss angle, δ, or the cotangent
of its phase angle, θ. (See Figs. 1 and 2.) (2011)
FIG. 2 Vector Diagram for Series Circuit
DISCUSSION—a:
D 5 tan δ 5 cotθ 5 X /R 5 G/ωC 5 1/ωC R (4)
p p p p p
where:
G = equivalent ac conductance,
X = parallel reactance,
p
R = equivalent ac parallel resistance,
p
C = parallel capacitance, and
p
ω = 2πf (sinusoidal wave shape assumed).
FIG. 3 Parallel Circuit
The reciprocal of the dissipation factor is the quality factor, Q,
sometimes called the storage factor. The dissipation factor, D, of the
capacitor is the same for both the series and parallel representations as
follows:
D 5 ωR C 5 1/ωR C (5)
s s p p
The relationships between series and parallel components are as fol-
lows:
FIG. 4 Series Circuit
C 5 C / 11D (6)
~ !
p s
2 2 2 2
R /R 5 ~11D !/D 5 11~1/D ! 5 l1Q
p s
(2011)
DISCUSSION—b: Series Representation—While the parallel represen- electric field strength, n—the magnitude of the vector force on
tation of an insulating material having a dielectric loss (Fig. 3) is
a point charge of unit magnitude and positive
usually the proper representation, it is always possible and occasionally
polarity. (2011) D4470
desirable to represent a capacitor at a single frequency by a capacitance,
C , in series with a resistance, R (Figs. 4 and 2). (2011)
electric strength—see dielectric strength.
s s
electrically conductive adhesive, n—adhesive which exhibits
drainage, n—of an insulating varnish, a measure of the
electrical conductivity. (2014)
variation in thickness from top to bottom of a varnish film
obtained on the surface of a vertically dipped coated panel
electrically conductive yarn, n—yarn that provides electrical
after a specified time and temperature. (1996) D115
conductivity and has been made either by blending a
conductive fiber with other fiber(s) or otherwise made
dressed crude mica, n—crude mica from which the dirt and
conductive on the surface. (2014)
rock have been mainly removed. (1996)
DISCUSSION—Some small pieces of inferior mica are produced and
electrification time, n—the time during which a steady direct
separated at this stage. This by-product is called splitting block, and can
potential is applied to electrical insulating materials before
be used for the production of splittings. (2011)
the current is measured. (2011)
electric breakdown voltage—see dielectric breakdown volt-
electrolytic capacitor paper, n—very pure, porous paper, 17
age. (2011)
to 100 μm thick, used to separate the metallic electrodes in
electrolytic capacitors. (2011)
electromagnetic shielding coating, n—coating that has an
electromagnetic shielding capability and can be applied onto
a substrate. (2014)
electromagnetic shielding fabric , n—fabric, woven or non-
woven, with an electromagnetic shielding capability. (2014)
electromagnetic shielding film, n—film with an electromag-
FIG. 1 Vector Diagram for Parallel Circuit netic shielding capability. (2014)
D1711 − 24
electromagnetic shielding plastic, n—polymeric material flat conductor cable, n—a cable of flat conductors. (2011)
with an electromagnetic shielding capability that is manu-
FR, n—a designation noting that an electrical insulating
factured by combining a plastic material with a conductive
material has been subjected to a standard test for flamma-
substance. (2014)
bility and has a rating in accordance with that stan-
electromagnetic shielding plate, n—plate-like electromag- dard. (2011)
DISCUSSION—The designation FR, when used in describing materials,
netic shielding material used for constructing an electromag-
does not imply flame or fire resistance. (2011)
netic shielding shell and which serves to shield electromag-
netic fields. (2014)
full-impulse-voltage wave, n—an aperiodic transient voltage
that rises rapidly to a maximum value, then falls less rapidly
electromagnetic shielding rubber, n—electromagnetic shield-
to zero. (2011) D3426
ing material formed by adding an electrically conductive
material to a rubber substrate, while retaining the elasto-
gel time, n—of solventless varnish, the time required, at a
meric characteristics of the rubber. (2014)
specified temperature, for a solventless varnish to be trans-
DISCUSSION—Materials typically used as conductive materials are
formed from a liquid state to a gel, as measured with a
silver, nickel, and carbon.
suitable gel time apparatus. (1996) D3056, D4733
electromagnetic shielding tape, n—tape with an electromag-
group AQL, n—the AQL assigned to a group of material
netic shielding function which is intended for adhesion.
properties. (2011)
(2014)
DISCUSSION—See 5.2.2 of Practice D3636 for additional information
about the meaning of AQL. (2011) D3636
embedding, n—a general term for all methods of surrounding
or enclosing components and assemblies with a substantial
guard electrode, n—one or more electrically conducting
thickness of electrically insulating solid or foam material
elements, arranged and connected in an electric instrument
with voids and interstices between the parts substantially
or measuring circuit so as to divert unwanted conduction or
filled. See potting, encapsulation, and dip encapsulation.
displacement currents from, or confine wanted currents to,
(2011)
the measurement device. (2011)
encapsulation, n—an embedding process utilizing removable
hard mica, n—mica which when slightly bent shows no
molds or other techniques in which the insulating material
tendency to delaminate. (2011)
forms the outer surfaces of the finished unit. (2011)
DISCUSSION—Thick pieces will give a hard sound when tapped or
dropped on a hard surface. (2011)
erosion, electrical, n—the progressive wearing away of elec-
trical insulation by the action of electrical discharges. (2011) harness, n—one or more hookup bundles tied, clamped, or
otherwise fitted together for final installation; used for
D2303
interconnecting electrical circuits. (2011)
erosion resistance, electrical, n—the quantitative expression
herringbones, n— in mica, numerous rulings that intersect to
of the amount of electrical erosion under specific
form a series of “V’s” with included angles of about
conditions. (2011) D2303
120°. (2011)
excess electrostatic charge, n—the algebraic sum of all
hookup bundle, n—a group of insulated conductors or hookup
positive and negative electric charges on the surface of, or in,
cables grouped into an assembly prior to installation, usually
a specific volume. (2011) D4470
with multiple breakouts. (2011)
failure—see dielectric failure.
hookup cable, n—two or more insulating conductors in a
films, n—trimmed mica split to specific ranges of thickness
common covering, or two or more insulated conductors
under 0.15 mm processed from block and thins. (2011)
twisted or molded together without a common covering, or
flashover (as related to electrical), n—an electrical discharge
one or more insulated conductors with a conductive shield
between two electrodes which occurs around the surface of
with or without an outer covering. (2011)
a solid dielectric in the surrounding medium (2019). D149,
hookup wire, n—an insulated conductor that is used to make
D3755
point-to-point connections in an electrical or electronic
flash point, n—the lowest temperature of a specimen, cor-
system. (2011)
rected to a pressure of 760 mm Hg (101.3 kPa), at which
impregnation time of paper, n—the time in seconds required
application of an ignition source causes any vapor from the
for a liquid of specified composition and viscosity to
specimen to ignite under specified conditions of test. (1996)
penetrate completely from one face of a sheet of paper to the
D115
other under certain prescribed conditions. (1996) D202
flat cable, n—any cable with two smooth or corrugated, but
inclusions, n—foreign matter in the mica.
essentially flat, surfaces. (2011)
air inclusions appear by transmitted light as grayish areas
flat conductor, n—a conductor with a width-to-thickness ratio and as silvery areas by reflected light. These are gaseous
arbitrarily chosen as five-to-one or greater. (2011) inclusions.
D1711 − 24
DISCUSSION—b—Loss index is the term agreed upon internationally.
clay inclusions appear by any light as areas of blue, gray,
In the United States κ" was formerly called the loss factor. (2011)
brown, and so forth, and are intrusions of earthy materials.
D150
mineral inclusions appear by transmitted light as areas of
deep distinct and highly saturated colors such as black,
lot, n—an entity of electrical insulating material or product
brown, green, red, and so forth. These are concentrated
which, insofar as is practicable, consists of a single type,
metallic oxides.
grade, class, size, or composition that was manufactured
vegetable and smokey inclusions appear by transmitted
under essentially the same conditions and is available to the
light as areas of pastel colors of low to medium satur
...

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: D1711 − 22 D1711 − 24
Standard Terminology Relating to
Electrical Insulation
This standard is issued under the fixed designation D1711; 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.
INTRODUCTION
This terminology is used in connection with testing and specifying solid electrical insulating
materials. Modifications to this terminology, reflecting common usage, may appear in particular test
methods, material specifications, practices, or other standards. Included herein are terms pertinent to
general applications, electrical insulating papers, mica, mica processing, processed mica forms,
hookup wire insulation, and partial discharge (corona).
1. Scope*
1.1 This terminology standard is a compilation of technical terms associated with testing and specifying solid electrical and
electronic insulating materials.
1.2 This terminology standard shall contain all definitions that are balloted specifically through Subcommittee D09.94 and through
D09 main committee and that are of general interest to standards associated with electrical and electronic insulating materials.
Those definitions shall be of importance to electrical and electronic insulating materials issues but need not be directly associated
with a specific standard under the jurisdiction of Committee D09 on Electrical and Electronic Insulating Materials.
1.3 It is intended that all definitions in this terminology standard originating in a specific standard under the jurisdiction of
Committee D09 be identical to definitions of the same terms as printed in standards of originating technical subcommittees, with
the exceptions of: (1) deletion of any part of the Discussion included in another standard that refers specifically to the use of a term
in that standard; (2) figure numbers and corresponding references; and (3) in this terminology standard, a parenthetical addition
of a reference to one or more technical standards in which the term is used and the year in which the term was added to this
compilation.
1.3.1 Definitions contained in this terminology standard which did not originate in a specific standard under the jurisdiction of
Committee D09, or which originated in a standard that has since been revised or withdrawn, and that have been appropriately
balloted, shall also be included in this terminology standard.
1.4 It is permissible to include symbols as part of the representation of terms, where appropriate.
1.5 It is not intended that this terminology standard include symbols (except as noted in 1.4). It is also permissible to include
acronyms and abbreviations referring directly to defined terms.
This terminology is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of Subcommittee
D09.94 on Editorial.
Current edition approved Sept. 1, 2022March 1, 2024. Published October 2022March 2024. Originally approved in 1960. Last previous edition approved in 20202022 as
D1711 – 20.D1711 – 22. DOI: 10.1520/D1711-22.10.1520/D1711-24.
*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
D1711 − 24
1.6 Revisions and additions to those definitions in this terminology standard which originate in a specific standard under the
jurisdiction of Committee D09 are to be made as a product of a collaborative effort between Subcommittee D09.94 and the
corresponding technical subcommittee of Committee D09, with Subcommittee D09.94 providing editorial advice to the technical
subcommittees.
1.7 Each definition in this terminology standard shall be accompanied by the year in which it was first incorporated into the
standard, placed at the end in parentheses. All discussions shall also carry a date; it is possible that the discussion date is different
from the definition date.
1.8 1.8.1 – 1.8.3 contain references to specific terminology standards that are relevant to specific electrical insulating materials or
applications. In case of conflict between a definition contained in Terminology D1711 and one contained in another standard, the
definition given in Terminology D1711 shall prevail.
1.8.1 For terms related to plastics, the applicable definitions are contained in Terminology D883.
1.8.2 For terms relating to fire, the applicable definitions are contained in Terminology E176 and ISO 13943. In case of conflict
between Terminology E176 and ISO 13943, the definitions given in Terminology E176 shall prevail.
1.8.3 For terms relating to precision and bias and associated issues, the applicable definitions are contained in Terminology E456.
1.9 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.
2. Referenced Documents
2.1 ASTM Standards:
D115 Test Methods for Testing Solvent Containing Varnishes Used for Electrical Insulation
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation
D176 Test Methods for Solid Filling and Treating Compounds Used for Electrical Insulation (Withdrawn 2013)
D202 Test Methods for Sampling and Testing Untreated Paper Used for Electrical Insulation
D257 Test Methods for DC Resistance or Conductance of Insulating Materials
D470 Test Methods for Crosslinked Insulations and Jackets for Wire and Cable
D883 Terminology Relating to Plastics
D1000 Test Methods for Pressure-Sensitive Adhesive-Coated Tapes Used for Electrical and Electronic Applications
D1676 Test Methods for Film-Insulated Magnet Wire
D1830 Test Method for Thermal Endurance of Flexible Sheet Materials Used for Electrical Insulation by the Curved Electrode
Method
D1868 Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in Evaluation of Insulation Systems
D2303 Test Methods for Liquid-Contaminant, Inclined-Plane Tracking and Erosion of Insulating Materials
D2304 Test Method for Thermal Endurance of Rigid Electrical Insulating Materials
D2307 Test Method for Thermal Endurance of Film-Insulated Round Magnet Wire
D2519 Test Method for Bond Strength of Electrical Insulating Varnishes by the Helical Coil Test
D2671 Test Methods for Heat-Shrinkable Tubing for Electrical Use
D2967 Test Method for Corner Coverage of Powder Coatings
D3032 Test Methods for Hookup Wire Insulation
D3056 Test Method for Gel Time of Solventless Varnishes
D3145 Test Method for Thermal Endurance of Electrical Insulating Varnishes by Helical Coil Method
D3214 Test Methods for Coating Powders and Their Coatings Used for Electrical Insulation (Withdrawn 2002)
D3288D3288/D3288M Test Methods for Magnet-Wire Enamels
D3312 Test Method for Percent Reactive Monomer in Solventless Varnishes
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.
The last approved version of this historical standard is referenced on www.astm.org.
D1711 − 24
D3353 Test Methods for Fibrous-Insulated Magnet Wire
D3382 Test Methods for Measurement of Energy and Integrated Charge Transfer Due to Partial Discharges (Corona) Using
Bridge Techniques
D3426 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials Using
Impulse Waves
D3636 Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
D3755 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials Under
Direct-Voltage Stress
D4313 Specification for General-Purpose, Heavy-Duty, and Extra-Heavy-Duty Crosslinked Chlorinated Polyethylene (CPE)
Jackets For Wire and Cable
D4323 Test Method for Hydrogen Sulfide in the Atmosphere by Rate of Change of Reflectance
D4470 Test Method for Static Electrification
D4496 Test Method for D-C Resistance or Conductance of Moderately Conductive Materials
D4733 Test Methods for Solventless Electrical Insulating Varnishes
D4880 Test Method for Salt Water Proofness of Insulating Varnishes Over Enamelled Magnet Wire
D4881 Test Method for Thermal Endurance of Varnished Fibrous- or Film-Wrapped Magnet Wire
D4882 Test Method for Bond Strength of Electrical Insulating Varnishes by the Twisted-Coil Test
D5288 Test Method for Determining Tracking Index of Electrical Insulating Materials Using Various Electrode Materials
(Excluding Platinum)
D6053 Test Method for Determination of Volatile Organic Compound (VOC) Content of Electrical Insulating Varnishes
E176 Terminology of Fire Standards
E456 Terminology Relating to Quality and Statistics
2.2 Other Standards:
4, 5
ANSI/ASQC A2-1987 Terms, Symbols, and Definitions for Acceptance Sampling
GB/T 26667 Terminology for Electromagnetic Shielding Materials
ISO 13943 Fire Safety-Vocabulary
3. Terminology
absorbing material, n—material capable of absorbing energy from an electromagnetic wave. (2014)
acceptable quality level (AQL), n—the maximum percent nonconforming which, for purposes of sampling inspection, is
considered satisfactory as a process average. (2011) D3636
acceptance number, n—the maximum allowable number of nonconformities for a given AQL and sample size (lot-sample
size). (2011) D3636
aging (act of), n—exposure of material to air or oil at a temperature and time as specified in the relevant material specification
for that material. (2013) D470, D4313, D4323
air chain, n—in mica, a series of air inclusions in the form of a chain or streak. (2011)
arc propagation, n—the movement of an electric arc from its point of inception to another location. (1996) D3032
arc tracking, n—the process producing tracks when arcs occur on or close to the insulation surface. (2011)
Arrhenius plot, n—a graph of the logarithm of thermal life as a function of the reciprocal of absolute temperature. (2011)
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
ASQC A2 has been superseded and replaced by ASQC 3534-2, published by the American Society for Quality, 600 North Plankinton Road, PO Box 3005, Milwaukee,
WI 53201 United States, www.asq.org.
Available from Standardization Administration of China, Haidian District, Beijing, People’s Republic of China.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
https://www.iso.org.
This term is defined in a way similar to the way it appears in the GB/T 26667 standard entitled, “Terminology for Electromagnetic Shielding Materials.”
D1711 − 24
DISCUSSION—
This is normally depicted as the best straight line fit, determined by least squares, of end points obtained at aging temperatures. It is important that
the slope, which is the activation energy of the degradation reaction, be approximately constant within the selected temperature range to ensure a valid
extrapolation. (2011) D2304
ash content of paper, n—the solid residue remaining after combustion of the paper under specified conditions, expressed as a
percentage of the dry mass of the original paper. (1996) D202
average discharge (corona) current (I ),n—the sum of the absolute magnitudes of the individual discharges during a certain
t
time interval divided by that time interval. (2011)
DISCUSSION—
When the discharges are measured in coulombs and the time interval in seconds, the calculated current will be in amperes. (2011)
t
Q 1Q 1222222Q
( 1 2 n
t
I 5 (1)
t
t 2 t
1 0
where:
I = average current, A,
t
t = starting time, s,
t = completion time, s, and
Q , Q , Q = partial discharge quantity in a corona pulse 1 through n, C.
1 2 n
D1868
binder tape—see core wrap (binder tape).
bond strength, n—a measure of the force required to separate surfaces which have been bonded together. (1996)
D2519, D3145, D4882
braid, n—(1) woven metallic wire used as a shield for insulated conductors and cables.
(2) A woven fibrous protective outer covering over an insulated conductor or cable. (2011)
breakdown voltage—see dielectric breakdown voltage.
bursting strength of paper, n—the hydrostatic pressure required to produce rupture of a circular area of the material under
specified test conditions. (1996) D202
cable wrap, n—paper used for mechanical protection or for space-filling (rather than as electrical insulation) in low-voltage
cables with nonmetallic sheaths. (2011)
capacitance, C,n—that property of a system of conductors and dielectrics which permits the storage of electrically separated
charges when potential differences exist between the conductors. (2011)
DISCUSSION—
Capacitance is the ratio of a quantity, q, of electricity to a potential difference, V. A capacitance value is always positive. The units are farads when
the charge is expressed in coulombs and the potential in volts (2011):
C 5 q/V (2)
D150
capacitor tissue, n—very thin (5 to 50 μm) pure, nonporous paper used as the dielectric in capacitors, usually in conjunction
with an insulating liquid. (2011)
coating powder, n—a heat-fusible, finely-divided solid resinous material used to form electrical insulating coatings. (1996)
D2967, D3214
D1711 − 24
concentricity, n—the ratio, expressed in percent, of the minimum wall thickness to the maximum wall thickness. (2011) D2671
concentric-lay conductor, n—a conductor composed of a central core surrounded by one or more layers of helically laid
strands. (2011)
DISCUSSION—
In the most common type of concentric-lay conductor, all strands are of the same size and the central core is a single strand. (2011)
conductance, insulation, n—the ratio of the total volume and surface current between two electrodes (on or in a specimen) to
the dc voltage applied to the two electrodes. (2011)
DISCUSSION—
Insulation conductance is the reciprocal of insulation resistance. (2011) D257
conductance, surface, n—the ratio of the current between two electrodes (on the surface of a specimen) to the dc voltage applied
to the electrodes. (2011)
DISCUSSION—
(Some volume conductance is unavoidably included in the actual measurement.) Surface conductance is the reciprocal of surface resistance. (2011)
D257
conductance, volume, n—the ratio of the current in the volume of a specimen between two electrodes (on or in the specimen)
to the dc voltage applied to the two electrodes. (2011)
DISCUSSION—
Volume conductance is the reciprocal of volume resistance. (2011) D257
conducting material (conductor), n—a material within which an electric current is produced by application of a voltage
between points on, or within, the material. (2011)
DISCUSSION—
The term “conducting material” is usually applied only to those materials in which a relatively small potential difference results in a relatively large
current since all materials appear to permit some conduction current. Metals and strong electrolytes are examples of conducting materials. (2011)
D4470
conductive fiber, n—fiber which is a conductive material or is otherwise made conductive on the surface. (2014)
conductive gasket, n—conductive material used at a joint to ensure effective conductive contact. (2014)
conductivity, surface, n—the surface conductance multiplied by that ratio of specimen surface dimensions (distance between
electrodes divided by the width of electrodes defining the current path) which transforms the measured conductance to that
obtained if the electrodes had formed the opposite sides of a square. (2011)
DISCUSSION—
Surface conductivity is expressed in siemens. It is popularly expressed as siemens/square (the size of the square is immaterial). Surface conductivity
is the reciprocal of surface resistivity. (2011) D257
conductivity, volume, n—the volume conductance multiplied by that ratio of specimen volume dimensions (distance between
electrodes divided by the cross-sectional area of the electrodes) which transforms the measured conductance to that conductance
obtained if the electrodes had formed the opposite sides of a unit cube. (2011)
DISCUSSION—
Volume conductivity is usually expressed in siemens/centimetre or in siemens/metre and is the reciprocal of volume resistivity. (2011) D257
conductor, n—a wire, or combination of wires not insulated from each other, suitable for carrying electric current. (1996) D1676
continuous partial discharges (continuous corona), n—discharges that recur at rather regular intervals; for example on
approximately every cycle of an alternating voltage or at least once per minute for an applied direct voltage. (2011) D1868
D1711 − 24
core wrap (binder tape), n—paper used to wrap groups of insulated wire into cable configuration prior to sheathing. (2011)
DISCUSSION—
Usually, this term is applied to telephone communication cables in which core wrap is not regularly subjected to voltage stress, but may be exposed
to surges from lightning strokes or other accidental events. (2011)
corona, n—visible partial discharges in gases adjacent to a conductor. (2011)
DISCUSSION—
This term has also been used to refer to partial discharges in general. (2011) D1868
critical property, n—a quantitatively measurable characteristic which is absolutely necessary to be met if a material or product
is to provide satisfactory performance for the intended use. (2011)
DISCUSSION—
In some situations, specification requirements coincide with customer usage requirements. In other situations, they may not coincide, being either more
or less stringent. More stringent sampling (for example, smaller AQL values) is usually used for measurement of characteristics which are considered
critical. The selection of sampling plans is independent of whether the term defect or nonconformity is appropriate. (2011) D3636
cross grains or reeves, n—in mica, tangled laminations causing imperfect cleavage. (2011)
crude mica—mica as mined; crude crystals with dirt and rock adhering. (2011)
crystallographic discoloration, n—in mica, discoloration appearing as bands of lighter or darker shades of basic color of a
block of mica. (1996)
DISCUSSION—
Such bands are generally parallel to the crystallographic faces of the crystal from which the block was separated. (2011)
defect, n—a departure of a quality characteristic from its intended level, or state, that occurs with a severity sufficient to cause
an associated product or service not to satisfy intended normal, or reasonably foreseeable, usage requirements. (2011)
DISCUSSION—
The terms “defect” and “nonconformity” and their derivatives are used somewhat interchangeably in the historical and current literature.
Nonconformity objectively describes the comparison of test results to specification requirements, while the term defect has a connotation of predicting
the failure of a product or service to perform its intended function in use. Since this latter connotation is often unintended, the term nonconformity
is preferred in full consensus standards. The selection of any sample plan is independent of whether the term defect or nonconformity is appropriate.
The term defect may be appropriate for specifications mutually agreed upon by a producer and a user where specific use conditions are clearly
understood. Even in these cases however, use the term defect with caution and consider substituting the term nonconformity.
For additional comments, see ANSI/ASQC A2-1987 that also states: “When a quality characteristic of a product or service is “evaluated” in terms
of conformance to specification requirements, the use of the term nonconformity is appropriate.” (2011) D3636
dielectric, n—a medium in which it is possible to maintain an electric field with little supply of energy from outside
sources. (2011)
DISCUSSION—
The energy required to produce the electric field is recoverable, in whole or in part. A vacuum, as well as any insulating material, is a dielectric. (2011)
dielectric breakdown voltage (electric breakdown voltage), n—the potential difference at which dielectric failure occurs
under prescribed conditions, in an electrical insulating material located between two electrodes. (See also Test Method D149,
Appendix X1.) (2011)
DISCUSSION—
The term dielectric breakdown voltage is sometimes shortened to “breakdown voltage.” (2011) D149
dielectric constant—see relative permittivity.
dielectric failure (under test), n—an event that is evidenced by an increase in conductance in the dielectric under test limiting
the electric field that can be sustained. (2011) D149
D1711 − 24
dielectric strength, n—the voltage gradient at which dielectric failure of the insulating material occurs under specific conditions
of test. (2011) D149, D176, D3755
dip encapsulation (a type of conformal coating),n—an embedding process in which the insulating material is applied by
immersion and without the use of an outer container. (2011)
DISCUSSION—
The coating so formed generally conforms with the contour of the embedded part. (2011)
dissipation factor (loss tangent) (tan δ), D,n—the ratio of the loss index to its relative permittivity or
D 5κ"/κ' (3)
It is also the tangent of its loss angle, δ, or the cotangent of its phase angle, θ. (See Figs. 1 and 2.) (2011)
DISCUSSION—
a:
D 5 tan δ5cotθ5X /R 5 G/ωC 5 1/ωC R (4)
p p p p p
where:
G = equivalent ac conductance,
X = parallel reactance,
p
R = equivalent ac parallel resistance,
p
C = parallel capacitance, and
p
ω = 2πf (sinusoidal wave shape assumed).
The reciprocal of the dissipation factor is the quality factor, Q, sometimes called the storage factor. The dissipation factor, D, of the capacitor is the
same for both the series and parallel representations as follows:
D 5ωR C 5 1/ωR C (5)
s s p p
The relationships between series and parallel components are as follows:
C 5 C / 11D (6)
~ !
p s
2 2 2 2
R /R 5 ~11D !/D 5 11~1/D !5 l1Q
p s
(2011)
DISCUSSION—
b: Series Representation—While the parallel representation of an insulating material having a dielectric loss (Fig. 3) is usually the proper
representation, it is always possible and occasionally desirable to represent a capacitor at a single frequency by a capacitance, C , in series with a
s
resistance, R (Figs. 4 and 2). (2011)
s
drainage, n—of an insulating varnish, a measure of the variation in thickness from top to bottom of a varnish film obtained on
the surface of a vertically dipped coated panel after a specified time and temperature. (1996) D115
dressed crude mica, n—crude mica from which the dirt and rock have been mainly removed. (1996)
DISCUSSION—
Some small pieces of inferior mica are produced and separated at this stage. This by-product is called splitting block, and can be used for the production
of splittings. (2011)
electric breakdown voltage—see dielectric breakdown voltage. (2011)
FIG. 1 Vector Diagram for Parallel Circuit
D1711 − 24
FIG. 2 Vector Diagram for Series Circuit
FIG. 3 Parallel Circuit
FIG. 4 Series Circuit
electric field strength, n—the magnitude of the vector force on a point charge of unit magnitude and positive polarity. (2011)
D4470
electric strength—see dielectric strength.
electrically conductive adhesive, n—adhesive which exhibits electrical conductivity. (2014)
electrically conductive yarn, n—yarn that provides electrical conductivity and has been made either by blending a conductive
fiber with other fiber(s) or otherwise made conductive on the surface. (2014)
electrification time, n—the time during which a steady direct potential is applied to electrical insulating materials before the
current is measured. (2011)
electrolytic capacitor paper, n—very pure, porous paper, 17 to 100 μm thick, used to separate the metallic electrodes in
electrolytic capacitors. (2011)
electromagnetic shielding coating, n—coating that has an electromagnetic shielding capability and can be applied onto a
substrate. (2014)
electromagnetic shielding fabric , n—fabric, woven or non-woven, with an electromagnetic shielding capability. (2014)
electromagnetic shielding film, n—film with an electromagnetic shielding capability. (2014)
D1711 − 24
electromagnetic shielding plastic, n—polymeric material with an electromagnetic shielding capability that is manufactured by
combining a plastic material with a conductive substance. (2014)
electromagnetic shielding plate, n—plate-like electromagnetic shielding material used for constructing an electromagnetic
shielding shell and which serves to shield electromagnetic fields. (2014)
electromagnetic shielding rubber, n—electromagnetic shielding material formed by adding an electrically conductive material
to a rubber substrate, while retaining the elastomeric characteristics of the rubber. (2014)
DISCUSSION—
Materials typically used as conductive materials are silver, nickel, and carbon.
electromagnetic shielding tape, n—tape with an electromagnetic shielding function which is intended for adhesion. (2014)
embedding, n—a general term for all methods of surrounding or enclosing components and assemblies with a substantial
thickness of electrically insulating solid or foam material with voids and interstices between the parts substantially filled. See
potting, encapsulation, and dip encapsulation. (2011)
encapsulation, n—an embedding process utilizing removable molds or other techniques in which the insulating material forms
the outer surfaces of the finished unit. (2011)
erosion, electrical, n—the progressive wearing away of electrical insulation by the action of electrical discharges. (2011) D2303
erosion resistance, electrical, n—the quantitative expression of the amount of electrical erosion under specific
conditions. (2011) D2303
excess electrostatic charge, n—the algebraic sum of all positive and negative electric charges on the surface of, or in, a specific
volume. (2011) D4470
failure—see dielectric failure.
films, n—trimmed mica split to specific ranges of thickness under 0.15 mm processed from block and thins. (2011)
flashover (as related to electrical), n—an electrical discharge between two electrodes which occurs around the surface of a solid
dielectric in the surrounding medium (2019). D149, D3755
flash point, n—the lowest temperature of a specimen, corrected to a pressure of 760 mm Hg (101.3 kPa), at which application
of an ignition source causes any vapor from the specimen to ignite under specified conditions of test. (1996) D115
flat cable, n—any cable with two smooth or corrugated, but essentially flat, surfaces. (2011)
flat conductor, n—a conductor with a width-to-thickness ratio arbitrarily chosen as five-to-one or greater. (2011)
flat conductor cable, n—a cable of flat conductors. (2011)
FR, n—a designation noting that an electrical insulating material has been subjected to a standard test for flammability and has
a rating in accordance with that standard. (2011)
DISCUSSION—
The designation FR, when used in describing materials, does not imply flame or fire resistance. (2011)
D1711 − 24
full-impulse-voltage wave, n—an aperiodic transient voltage that rises rapidly to a maximum value, then falls less rapidly to
zero. (2011) D3426
gel time, n—of solventless varnish, the time required, at a specified temperature, for a solventless varnish to be transformed from
a liquid state to a gel, as measured with a suitable gel time apparatus. (1996) D3056, D4733
group AQL, n—the AQL assigned to a group of material properties. (2011)
DISCUSSION—
See 5.2.2 of Practice D3636 for additional information about the meaning of AQL. (2011) D3636
guard electrode, n—one or more electrically conducting elements, arranged and connected in an electric instrument or
measuring circuit so as to divert unwanted conduction or displacement currents from, or confine wanted currents to, the
measurement device. (2011)
hard mica, n—mica which when slightly bent shows no tendency to delaminate. (2011)
DISCUSSION—
Thick pieces will give a hard sound when tapped or dropped on a hard surface. (2011)
harness, n—one or more hookup bundles tied, clamped, or otherwise fitted together for final installation; used for
interconnecting electrical circuits. (2011)
herringbones, n— in mica, numerous rulings that intersect to form a series of “V’s” with included angles of about 120°. (2011)
hookup bundle, n—a group of insulated conductors or hookup cables grouped into an assembly prior to installation, usually
with multiple breakouts. (2011)
hookup cable, n—two or more insulating conductors in a common covering, or two or more insulated conductors twisted or
molded together without a common covering, or one or more insulated conductors with a conductive shield with or without an
outer covering. (2011)
hookup wire, n—an insulated conductor that is used to make point-to-point connections in an electrical or electronic
system. (2011)
impregnation time of paper, n—the time in seconds required for a liquid of specified composition and viscosity to penetrate
completely from one face of a sheet of paper to the other under certain prescribed conditions. (1996) D202
inclusions, n—foreign matter in the mica.
air inclusions appear by transmitted light as grayish areas and as silvery areas by reflected light. These are gaseous inclusions.
clay inclusions appear by any light as areas of blue, gray, brown, and so forth, and are intrusions of earthy materials.
mineral inclusions appear by transmitted light as areas of deep distinct and highly saturated colors such as black, brown,
green, red, and so forth. These are concentrated metallic oxides.
vegetable and smokey inclusions appear by transmitted light as areas of pastel colors of low to medium saturation such as pale
yellow, pale brown, pale green, and so forth. These are dispersed metallic oxides. The term“ vegetable” is a misnomer. (2011)
infrared, adj—pertaining to the region of the electromagnetic spectrum from approximately 0.78 to 300 μm. (1996)
D3288D3288/D3288M
insulated conductor, n—a conductor covered by a layer or layers of insulating material and whose prime function is to carry
current in an electric circuit. (2011)
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