IEC/IEEE 62582-3:2012

IEC/IEEE 62582-3
Edition 1.0 2012-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –
Electrical equipment condition monitoring methods –
Part 3: Elongation at break
Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Méthodes de surveillance de l’état des matériels
électriques –
Partie 3: Allongement à la rupture

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IEC/IEEE 62582-3
Edition 1.0 2012-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –

Electrical equipment condition monitoring methods –

Part 3: Elongation at break
Centrales nucléaires de puissance – Instrumentation et contrôle-commande

importants pour la sûreté – Méthodes de surveillance de l’état des matériels

électriques –
Partie 3: Allongement à la rupture

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX T
ICS 27.120.20 ISBN 978-2-83220-424-5

– 2 – 62582-3 © IEC/IEEE:2012
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope and object . 8
2 Terms and definitions . 8
3 General description . 9
4 Applicability and reproducibility . 9
5 Measurement procedure . 9
5.1 Stabilisation of the polymeric materials . 9
5.2 Sampling . 9
5.2.1 General . 9
5.2.2 Sample requirements . 10
5.3 Specimen preparation . 10
5.3.1 General . 10
5.3.2 Dumb-bell specimens . 11
5.3.3 Tubular specimens . 11
5.3.4 O-ring specimens . 11
5.4 Instrumentation . 11
5.4.1 Tensile test machine . 11
5.4.2 Calibration . 11
5.4.3 Use of extensometers . 11
5.5 Tensile elongation measurement method. 12
5.5.1 Conditioning . 12
5.5.2 Dimensions of test specimens . 12
5.5.3 Clamping . 12
5.5.4 Testing speed . 12
5.5.5 Recording data . 13
5.5.6 Calculation of results . 13
5.6 Measurement report . 14
Annex A (informative) Shape and dimensions of test specimens . 15
Annex B (informative) Preparation of test specimens from cable samples . 18
Annex C (informative) Typical load versus elongation curves . 20
Annex D (normative) Dies for cutting dumb-bell specimens . 22
Annex E (informative) Example of a measurement report from tensile elongation
measurements . 23
Bibliography . 24

Figure A.1 – Shape of dumb-bell specimens . 15
Figure A.2 – Fitting end tabs to tubular specimens . 16
Figure A.3 – Fitting soft inserts to tubular specimens . 17
Figure A.4 – Mounting of O-ring specimens in the test machine . 17
Figure C.1 – Typical load-elongation curves . 20
Figure C.2 – Typical load-time curve with a slipping specimen . 21
Figure D.1 – Suitable cutters for dumb-bell specimens . 22

62582-3 © IEC/IEEE:2012 – 3 –
Table 1 – Testing speeds for elongation measurements . 12
Table A.1 – Recommended dimensions for dumb-bell specimens . 15

– 4 – 62582-3 © IEC/IEEE:2012
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL IMPORTANT TO SAFETY –
ELECTRICAL EQUIPMENT CONDITION MONITORING METHODS –

Part 3: Elongation at break
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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IEEE Standards documents are developed within IEEE Societies and Standards Coordinating Committees of the
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IEC collaborates closely with IEEE in accordance with conditions determined by agreement between the two
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2) The formal decisions of IEC on technical matters express, as nearly as possible, an international consensus of
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3) IEC/IEEE Publications have the form of recommendations for international use and are accepted by IEC
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or IEEE or their directors, employees, servants or agents including individual
experts and members of technical committees and IEC National Committees, or volunteers of IEEE Societies
and the Standards Coordinating Committees of the IEEE Standards Association (IEEE-SA) Standards Board,
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IEC/IEEE Publication or any other IEC or IEEE Publications.
8) Attention is drawn to the normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that implementation of this IEC/IEEE Publication may require use of
material covered by patent rights. By publication of this standard, no position is taken with respect to the
existence or validity of any patent rights in connection therewith. IEC or IEEE shall not be held responsible for
identifying Essential Patent Claims for which a license may be required, for conducting inquiries into the legal
validity or scope of Patent Claims or determining whether any licensing terms or conditions provided in
connection with submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or
non-discriminatory. Users of this standard are expressly advised that determination of the validity of any patent
rights, and the risk of infringement of such rights, is entirely their own responsibility.

62582-3 © IEC/IEEE:2012 – 5 –
International Standard IEC/IEEE 62582-3 has been prepared by subcommittee 45A:
Instrumentation and control of nuclear facilities, of IEC technical committee 45: Nuclear
instrumentation, in cooperation with the Nuclear Power Engineering Committee of the Power
& Energy Society of the IEEE , under the IEC/IEEE Dual Logo Agreement.
This publication is published as an IEC/IEEE Dual Logo standard.
The text of this standard is based on the following IEC documents:
FDIS Report on voting
45A/887/FDIS 45A/891/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
International standards are drafted in accordance with the rules given in the ISO/IEC
Directives, Part 2.
A list of all parts of IEC/IEEE 62582, under the general title Nuclear power plants –
Instrumentation and control important to safety – Electrical equipment condition monitoring
methods, can be found on the IEC website.
The IEC Technical Committee and IEEE Technical Committee have decided that the contents
of this publication will remain unchanged until the stability date indicated on the IEC web site
under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
———————
A list of IEEE participants can be found at the following URL: http://standards.ieee.org/downloads/62582-
3/62582-3-2012/62582-3-2012_wg-participants.pdf.

– 6 – 62582-3 © IEC/IEEE:2012
INTRODUCTION
a) Technical background, main issues and organisation of the standard
This part of this IEC/IEEE standard specifically focuses on elongation at break methods for
condition monitoring for the management of ageing of electrical equipment installed in nuclear
power plants. The method is primarily suited to samples taken from equipment that are based
on thermoplastic or elastomeric polymers.
This part of IEC/IEEE 62582 is the third part of the IEC/IEEE 62582 series. It contains
detailed descriptions of condition monitoring based on elongation at break measurements.
The IEC/IEEE 62582 series is issued with a joint logo which makes it applicable to
management of ageing of electrical equipment qualified to IEEE as well as IEC Standards.
Historically, IEEE Std 323-2003 introduced the concept and role that condition based
qualification could be used in equipment qualification as an adjunct to qualified life. In
equipment qualification, the condition of the equipment for which acceptable performance was
demonstrated is the qualified condition. The qualified condition is the condition of equipment,
prior to the start of a design basis event, for which the equipment was demonstrated to meet
the design requirements for the specified service conditions.
Significant research has been performed on condition monitoring techniques and the use of
these techniques in equipment qualification as noted in NUREG/CR-6704, vol.2
(BNL-NUREG-52610) and JNES-SS-0903, 2009.
It is intended that this IEC/IEEE standard be used by test laboratories, operators of nuclear
power plants, systems evaluators and licensors.
b) Situation of the current Standard in the structure of the IEC SC 45A standard series
Part 3 of IEC/IEEE 62582 is the third level IEC SC 45A document tackling the specific issue of
application and performance of elongation at break measurements in management of ageing
of electrical instrument and control equipment in nuclear power plants.
Part 3 of IEC/IEEE 62582 is to be read in association with part 1 of IEC/IEEE 62582, which
provides requirements for application of methods for condition monitoring of electrical
equipment important to safety of nuclear power plants.
For more details on the structure of the IEC SC 45A standard series, see item d) of this
introduction.
c) Recommendations and limitations regarding the application of this Standard
It is important to note that this Standard establishes no additional functional requirements for
safety systems.
d) Description of the structure of the IEC SC 45A standard series and relationships
with other IEC documents and other bodies documents (IAEA, ISO)
The top-level document of the IEC SC 45A standard series is IEC 61513. It provides general
requirements for I&C systems and equipment that are used to perform functions important to
safety in NPPs. IEC 61513 structures the IEC SC 45A standard series.
IEC 61513 refers directly to other IEC SC 45A standards for general topics related to
categorization of functions and classification of systems, qualification, separation of systems,
defence against common cause failure, software aspects of computer-based systems,

62582-3 © IEC/IEEE:2012 – 7 –
hardware aspects of computer-based systems, and control room design. The standards
referenced directly at this second level should be considered together with IEC 61513 as a
consistent document set.
At a third level, IEC SC 45A standards not directly referenced by IEC 61513 are standards
related to specific equipment, technical methods, or specific activities. Usually these
documents, which make reference to second-level documents for general topics, can be used
on their own.
A fourth level extending the IEC SC 45 standard series, corresponds to the Technical Reports
which are not normative.
IEC 61513 has adopted a presentation format similar to the basic safety publication
IEC 61508 with an overall safety life-cycle framework and a system life-cycle framework.
Regarding nuclear safety, it provides the interpretation of the general requirements of
IEC 61508-1, IEC 61508-2 and IEC 61508-4, for the nuclear application sector, regarding
nuclear safety. In this framework IEC 60880 and IEC 62138 correspond to IEC 61508-3 for
the nuclear application sector. IEC 61513 refers to ISO as well as to IAEA GS-R-3 and IAEA
GS-G-3.1 for topics related to quality assurance (QA).
The IEC SC 45A standards series consistently implements and details the principles and
basic safety aspects provided in the IAEA code on the safety of NPPs and in the IAEA safety
series, in particular the Requirements NS-R-1, establishing safety requirements related to the
design of Nuclear Power Plants, and the Safety Guide NS-G-1.3 dealing with instrumentation
and control systems important to safety in Nuclear Power Plants. The terminology and
definitions used by SC 45A standards are consistent with those used by the IAEA.
NOTE It is assumed that for the design of I&C systems in NPPs that implement conventional safety functions (e.g.
to address worker safety, asset protection, chemical hazards, process energy hazards) international or national
standards would be applied, that are based on the requirements of a standard such as IEC 61508.

– 8 – 62582-3 © IEC/IEEE:2012
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL IMPORTANT TO SAFETY –
ELECTRICAL EQUIPMENT CONDITION MONITORING METHODS –

Part 3: Elongation at break
1 Scope and object
This part of IEC/IEEE 62582 contains methods for condition monitoring of organic and
polymeric materials in instrumentation and control systems using tensile elongation
techniques in the detail necessary to produce accurate and reproducible measurements. It
includes the requirements for selection of samples, the measurement system and conditions,
and the reporting of the measurement results.
The different parts of IEC/IEEE 62582 are measurement standards, primarily for use in the
management of ageing in initial qualification and after installation. Part 1 of IEC/IEEE 62582
General includes requirements for the application of the other parts of IEC/IEEE 62582 and
some elements which are common to all methods. Information on the role of condition
monitoring in qualification of equipment important to safety is found in IEEE Std 323.
This standard is intended for application to non-energised equipment.
2 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
2.1
elongation
tensile strain expressed as a percentage of the test length, produced in the piece by a tensile
stress
[SOURCE: ISO 37:2011]
2.2
elongation at break
tensile strain in the test length at the breaking point
[SOURCE: ISO 37:2011]
2.3
nominal elongation at break
tensile strain, expressed as a percentage of the specimen length between the grips, produced
in the specimen at the breaking point
2.4
gauge length
initial distance between the gauge marks on the central part of the test specimen. It is
expressed in millimetres (mm)
Note 1 to entry: See figures of the test specimens in the relevant part of ISO 527.
[SOURCE: ISO 527-1:2012]
62582-3 © IEC/IEEE:2012 – 9 –
2.5
speed of testing
rate of separation of the grips of the testing machine during the test. It is in millimetres per
minute (mm/min)
[SOURCE: ISO 527-1:2012]
3 General description
A test specimen is extended along its longitudinal axis at constant speed until the specimen
fractures. During the test, the load sustained on the specimen and its elongation are
measured. For this standard, elongation at break is the measured parameter.
NOTE Elongation at break rather than tensile strength is used because for some polymers, particularly
thermoplastics, the strength may remain consistently equal to the yield strength after ageing even when the
elongation has decreased to < 50 % absolute.
4 Applicability and reproducibility
The method is related to the long chain molecular structure of the polymer. As degradation
proceeds, changes in the molecular structure occur as a result of cross-linking, chain
scission, oxidation and other degradation mechanisms. These changes usually decrease the
elongation at break.
This method is primarily suited to samples taken from equipment that are based on
thermoplastic or elastomeric polymers. The method is generally not suitable for fibre
reinforced polymers or resins such as epoxides.
The method cannot be used in the field in the nuclear power plant but uses samples taken
from the plant, which are then measured in the laboratory. Each tensile elongation
measurement in the laboratory can take between 5 min and 10 min to complete.
NOTE Round robin tests using a method close to the current standard have shown a typical laboratory variation
in results of measurements of elongation at break on identical specimens of 8 % to 10 %.
The mechanical properties of some polymeric materials may be affected by the moisture
content. Most organic and polymeric materials currently used in-containment are not
significantly hygroscopic. However, if hygroscopic materials are used, the influence of the
moisture content of the material on elongation at break may need to be considered,
particularly after artificial thermal ageing as a consequence of long term exposure to high
temperature in an oven.
5 Measurement procedure
5.1 Stabilisation of the polymeric materials
An appropriate time period shall be allowed for the polymeric materials in recently
manufactured equipment to stabilise before any condition monitoring or accelerated ageing
programmes are carried out. The time period over which the polymeric materials stabilise is
normally dependent on the processing additives and polymer composition. If manufacturers’
stabilisation time data are not available, a period of 6 months should be allowed before
commencing ageing to allow initial values from unaged samples to become stable.
5.2 Sampling
5.2.1 General
Measurements of tensile elongation provide information on the status of the equipment only at
the specific location which has been sampled. Knowledge of the environmental conditions in

– 10 – 62582-3 © IEC/IEEE:2012
representative areas during plant operation is a prerequisite for selecting sample locations for
condition monitoring. It is important that these locations represent as wide a range of ageing
conditions as possible with special consideration given to locations where ageing conditions
could be severe, e.g. hotspots. The location of the sampling and available information about
the environmental time history at the sample location selected shall be documented.
Sampling procedures shall comply with local instructions, taking into account safety of
personnel and equipment. Handling of equipment during removal of samples from the plant
should be minimised e.g. cables should not be bent more than is necessary to remove the
sample.
Measurements of elongation at break are formulation dependent and may be sensitive to
manufacturing variations, such as porosity. Any changes in formulation need to be evaluated.
5.2.2 Sample requirements
When preparing samples from whole cables that have been aged in the laboratory or in a
deposit, samples shall be taken from sections of the cable at least 100 mm from the ends,
unless such ends have been sealed during ageing.
In order to obtain reasonable confidence, a minimum of 5 test specimens is required for
elongation measurements to be made on one specific sample. However, it is recognised that
in some cases e.g. in samples taken from hot-spots, there may be insufficient material
available for this minimum to be satisfied.
The specimens may be prepared from equipment taken from the sampling location or,
alternatively, be prepared in advance and placed in the sample locations.
Care shall be taken to avoid unsuitable conditions in storage during the time period between
sampling and measurements. It is recommended that samples be stored in the dark at
temperatures not exceeding 25 °C and at humidity conditions within 45 % and 75 %.
5.3 Specimen preparation
5.3.1 General
When elongation tests are being carried out as part of a condition monitoring programme
involving comparative and consecutive measurements, identical specimen preparation method
and shape and dimensions of the specimen shall be used.
The type of specimen used for elongation measurements will depend on the geometry of the
equipment being sampled. Where possible, dumb-bell specimens shall be used. For some
equipment, e.g. the wire insulation in small diameter cables, dumb-bell specimens cannot be
prepared and tubular specimens shall be used as specified in 5.3.2. Moulded O-rings may
also be used as test specimens, where appropriate.
Dumb-bell or tubular specimens, or moulded O-rings are the most common form of specimens
used for condition monitoring. For some equipment alternative specimen geometries may be
necessary.
Specimens prepared from equipment before ageing, for example for use in a sacrificial
deposit, may be used. Care shall be taken that diffusion-limited oxidation is not an issue when
using pre-prepared specimens compared with those prepared after ageing.
NOTE 1 Preparation of test specimens from aged samples can be difficult – see Annex B for suggested
approaches for preparing such material.
NOTE 2 Recent studies have shown little significant difference between the oxidation of samples aged as whole
cables and those aged as prepared specimens (see Bibliography JNES-SS-0903), for small diameter cables in a
limited number of specific materials.

62582-3 © IEC/IEEE:2012 – 11 –
5.3.2 Dumb-bell specimens
Recommendations for the shape and dimensions of dumb-bell specimens are given in Annex
A. The test specimens shall be cut from the specimen using a suitable die (see Annex D).
In samples used for condition monitoring, there is usually only a limited amount of material
available. For this reason, smaller specimens than are usually used for tensile measurements
may be necessary.
5.3.3 Tubular specimens
Tubular specimens are used for equipment such as cable insulation where the core diameter
is too small to enable dumb-bell specimens to be cut. Tubular specimens are prepared by
removing the conductor from lengths of the insulation material. The overall length of the
stripped insulation shall be a minimum of 50 mm.
Care shall be taken to avoid damage to the polymeric insulation when stripping out the
conductor. See Annex B for suggested methods of preparing specimens.
With this type of specimen, end tabs or soft inserts are needed to prevent breakage in the
grips of the tensile testing machine, as detailed in Annex A.
5.3.4 O-ring specimens
Moulded O-rings may be used as the test specimens. It is essential that the same specimen
dimensions are used for both unaged and aged samples for condition monitoring. O-ring
samples may be taken from aged equipment.
5.4 Instrumentation
5.4.1 Tensile test machine
The instrument used for tensile elongation measurements shall be capable of measuring the
load exerted on the specimen and the separation between the specimen grips during
continuous stretching of the specimen at a constant rate. The test machine shall be capable
–1 –1
of testing speeds between 10 mm∙min and 100 mm∙min with a tolerance of ± 10 %.
Specimen grips shall be attached to the test machine so that the axis of the specimen
coincides with the direction of pull through the centre line of the grip assembly. The test
specimen shall be held such that slip relative to the grips is prevented. Pneumatic grips are
preferred to mechanical grips. The clamping system shall not cause undue stress on the
specimen resulting in potential premature fracture at the grips.
For the testing of O-ring specimens, the test machine shall have two pulleys or rounded pins
attached, one to the fixed part and one to the moving cross-head. These pulleys or pins shall
be aligned along the direction of pull and shall have a diameter no greater than one third of
the O-ring’s initial internal diameter and not less than 3 times the cord diameter.
The load indicator shall be capable of showing the tensile load carried by the specimen and
indicate the load value with an accuracy of at least 1 % of the actual value.
5.4.2 Calibration
The instrument shall be calibrated according to the manufacturer’s recommendations for the
load and elongation range appropriate for the specimens being tested.
5.4.3 Use of extensometers
Measurement of the grip separation or crosshead travel from a tensile test machine calibrated
to manufacturers’ specifications shall provide the specimen elongation during the tensile test.

– 12 – 62582-3 © IEC/IEEE:2012
An extensometer may be used as an alternative method of measuring elongation. If used, it
shall be of the non-contacting type. Non-contacting video extensometers are available which
can be used to measure specimen elongations to high levels of accuracy if required. If such
extensometers are used, a pair of marks shall be made on the surface of the specimen within
the straight section of the specimen. The distance between these marks shall be equal to the
gauge length for dumb-bell specimens and be 20 mm for tubular specimens.
The same method for measuring elongation of the specimen shall be used for both aged and
unaged samples.
5.5 Tensile elongation measurement method
5.5.1 Conditioning
Specimens shall be conditioned at a laboratory temperature of (25 ± 5) °C and a relative
humidity of 45 % to 75 % for at least 3 h prior to testing.
5.5.2 Dimensions of test specimens
If tensile strength is to be measured as subsidiary information from the tensile test, then the
dimensions of the test specimen shall be determined as follows.
For dumb-bell specimens the width and thickness shall be measured in the gauge length
section of the specimen. Dimensions shall be measured to the nearest 0,1 mm using a
suitable instrument such as a vernier calliper or dial gauge.
For tubular specimens, the diameter and thickness shall be measured. Optical measurement
of the thickness at a number of radial locations around the specimen shall be made. If
practical, 6 locations are recommended. Where the thickness is variable, e.g. where insulation
overlays a stranded conductor, a best estimate shall be made of the cross-sectional area.
For O-ring specimens, the internal diameter and radial thickness shall be measured. The
internal diameter shall be measured using a calibrated cone gauge or other suitable
measuring equipment.
5.5.3 Clamping
For dumb-bell and tubular test specimens, the specimen shall be placed in the test grips,
ensuring that the longitudinal axis of the specimen is aligned with the axis of the testing
machine. The grips shall be tightened evenly and firmly to avoid slippage of the test
specimen. Grip separation shall be such that only the wide sections of dumb-bell specimens
are in contact with the grips. For tubular specimens, the grip separation shall be 30 mm.
For O-ring samples, the specimen shall be placed over the pulleys or pins attached to the
fixed and moving cross-head of the test machine, ensuring that the specimen is not twisted.
5.5.4 Testing speed
The recommended testing speeds are shown in Table 1. The same test speed shall be used
for all tests on the same material.
Table 1 – Testing speeds for elongation measurements
–1
Specimen type Testing speed (mm∙min )
Dumb-bell specimens – types 1, 1A and 2 20
Dumb-bell specimens – type 3 10
Tubular specimens 50
O-ring specimens 50
62582-3 © IEC/IEEE:2012 – 13 –

The types refer to Annex A, Table A.1.
These testing speeds are much slower than normally used for tensile testing of polymeric
specimens for QA purposes but are recommended because slower test speeds tend to give
more reproducible results. Also, the measurements may not necessarily be directly
comparable with tests made at higher speeds. For this reason elongation at break values
derived from tests performed with higher speeds may not be appropriate as reference values
for ageing monitoring. In condition monitoring tests, the amount of material available for
testing is very limited and there is often no scope for the preparation of additional specimens.
5.5.5 Recording data
The load exerted on the specimen and the corresponding distance between the grips shall be
recorded during the test, preferably using an automated recording system which can display
the load-elongation curve during the test. The test shall be continued until the specimen
breaks.
Examples of typical load-elongation curves are shown in Annex C.
5.5.6 Calculation of results
For dumb-bell and tubular specimens, the elongation at break is calculated from
E − E
b 0
ε (%)= 100× (1)
E
Where ε is the elongation at break (expressed as a percentage), E is the initial distance
between the specimen grips and E is the distance between grips at break.
b
If a non-contacting extensometer has been used during the test, the parameters E and E
0 b
represent the initial distance between the marks on the specimen and the distance between
the marks at break, respectively.
For O-ring specimens, the elongation at break is given by
πd+ 2L − C
b
ε(%)= 100× (2)
C
where L is the distance between the pulley centres at break, C is the initial internal
b
circumference of the ring and d is the diameter of the pulleys.
NOTE 1 The calculation of elongation assumes negligible friction between the test rig pulleys or pins and the O-
ring material.
The arithmetic mean and standard deviation of the test results shall be calculated. Data from
any specimens which broke in the grips or slipped from the grips shall not be included in the
calculation of the mean. Any such data shall be reported separately.
NOTE 2 The tensile strength of the test specimens can also be extracted from the test as subsidiary data. The
tensile strength is calculated on the basis of the cross-sectional area of the specimen in the gauge length:
F
(3)
σ=
A
where σ is the tensile strength, expressed in MPa; F is the measured load at break, measured in Newton; A is the
initial cross-sectional area of the specimen, expressed in mm . The cross-sectional area for tubular specimens is
given by
– 14 – 62582-3 © IEC/IEEE:2012
(4)
A=π× (D−δ )×δ
where D is the mean value of the outer diameter and δ is the mean value of the thickness (see clause 5.5.2).
5.6 Measurement report
The measurement report shall include the following items.
a) Identification of the equipment sampled. This shall include
• details of the material being sampled e.g. the generic polymer type, specific
formulation numbers,
• where the sample was taken from,
• for samples taken in plant, location within the plant.
b) Pre-history of the equipment sampled. This shall include
• time in service, or ageing time for laboratory aged samples,
• the environmental conditions to which it has been exposed, e.g. temperature,
radiation,
• stabilisation time for unaged samples.
c) Place and date of the measurements.
d Number of specimens measured (5.2.2).
e) Details of specimen preparation (5.3 and Annex B).
f) Specimen type – dumb-bell/tube/ring and type of end tab/insert used, dimensions of
specimen; indicate whether specimens prepared before or after ageing (5.3 and 5.5.2).
g) Instrument used and software version used for analysis (5.4.1).
h) Calibration procedure (5.4.2).
i) Extensometer type used, if any (5.4.3).
j) Type of grips used to clamp specimens or pulley diameter for O-ring specimens (5.5.3).
k) Test speed used (5.5.4).
l) Whether elongation calculated from gauge length, using an extensometer, or nominal
elongation (5.5.6).
m) Individual elongation values (in %), mean values, and standard deviation; indicate in a
comments column any values excluded from calculation of the mean because of failure in
the grips or slippage. If strength values (in MPa) have also been calculated, these should
be included as subsidiary data.
n) Examples of typical load versus elongation plots. Any atypical plots shall also be included.

62582-3 © IEC/IEEE:2012 – 15 –
Annex A
(informative)
Shape and dimensions of test specimens

A.1 Preparation of dumb-bell specimens
The recommended shape for dumb-bell test specimens is shown in Figure A.1 with
dimensions as specified in Table A.1.
Dumb-bell specimens may be used with dimensions different from those given in Table A.1,
e.g. conforming to National Standards. However, it is important for reproducibility that the
same dimensions are used for both baseline measurements and samples taken from aged
material.
The test specimens shall be cut from the equipment sample (e.g. a section of cable) using a
suitable die, such as described in Annex D.
Specimens should not be prepared from slab samples, since these are not necessarily
representative of the material. Slab samples are usually considerably thicker than the material
used in equipment such as cables. This may raise issues of diffusion-limited oxidation and
differences in orientation of the molecular structure if slab samples are used.

= =
l
IEC  1978/12
Key
l is the gauge length
Figure A.1 – Shape of dumb-bell specimens
Table A.1 – Recommended dimensions for dumb-bell specimens
Dimension Type 1 Type 1A Type 2 Type 3
mm
Overall length – minimum 115 100 75 50
Width of ends
25 ± 1 25 ± 1 12,5 ± 1 8,5 ± 0,5
Length of narrow portion
33 ± 2 22 ± 1 25 ± 1 16 ± 1
Width of narrow portion
6 ± 0,2 5 ± 0,1 4 ± 0,1 4 ± 0,1
Gauge length 25 ± 1 20 ± 0,5 20 ± 0,5 10 ± 0,5
NOTE Type 1 is equivalent to ASTM D-412-C.

A.2 Tubular specimens
Tubular specimens are used for equipment such as cable insulation where the core diameter
is too small to enable dumb-bell specimens to be cut. Tubular specimens are prepared by

– 16 – 62582-3 © IEC/IEEE:2012
removing the conductor from lengths of the insulation material. The overall length of the
stripped insulation shall be a minimum of 50 mm.
Care shall be taken to avoid damage to the polymeric insulation when stripping out the
conductor. See Annex B for suggested methods of preparing specimens.
With this type of specimen, end tabs or soft inserts are needed to prevent breakage in the
grips of the tensile testing machine. For tubular specimens with outside diameters of < 4 mm,
end tabs shall be fitted as in Figure A.2. For larger diameter tubular specimens, soft inserts
shall be used as in Figure A.3.
The end tabs and/or inserts need to be of polymeric material of similar modulus to the
material being tested. The combination of end tabs and/or inserts are used to avoid excessive
stress in the specimen at the clamping position. This emulates the use of dumb-bell
specimens, where stress is concentrated in the gauge length during the test.
To prepare tubular specimens for testing, cut the specimen to a length of 50 mm. For tubular
specimens < 4 mm in diameter, cut two end tabs 8 mm in length and slide them over the ends
of the sp
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