IEC TS 61244-3:2005

TECHNICAL IEC
SPECIFICATION TS 61244-3
Second edition
2005-11
Long-term radiation ageing in polymers –
Part 3:
Procedures for in-service monitoring
of low-voltage cable materials

Reference number
IEC/TS 61244-3:2005(E)
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TECHNICAL IEC
SPECIFICATION TS 61244-3
Second edition
2005-11
Long-term radiation ageing in polymers –
Part 3:
Procedures for in-service monitoring
of low-voltage cable materials

 IEC 2005  Copyright - all rights reserved
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– 2 – TS 61244-3  IEC:2005(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.7
2 Normative references .7
3 Abbreviations .7
4 Requirements of a monitoring technique.8
5 Techniques available.8
5.1 General .8
5.2 Local tests without sampling.9
5.3 Local tests with micro-sampling.11
6 Summary.14

Bibliography.28

Figure 1 – Schematic diagram showing the operating principles of the sonic velocity
meter [1] .16
Figure 2 – Sonic velocity test results [3].17
Figure 3 – Variation in IR absorbance with wavelength for PVC material and the use of
first derivative to eliminate baseline shifts [1].18
Figure 4 – Correlation of first derivative of IR absorbance at 1 640 nm to 1 650 nm and
elongation at break for thermal ageing of PVC at 110 °C [1] .19
Figure 5 – Schematic diagram and photographs of prototype torque tester .20
Figure 6 – Elongation at break versus torque value for flame-retardant PVC cables
thermally aged at 158 °C [5] .21
Figure 7 – Elongation at break versus torque value for PVC cables exposed to
sequential radiation ageing to 0,5 MGy and thermal ageing at 120 °C [5].21
Figure 8 – Elongation at break versus torque value for PVC cables thermally aged at
120 °C [5] .22
Figure 9 – Correlation of tensile elongation with modulus measurements made using
the modulus profiling apparatus for a CSPE jacket aged at the five indicated
temperatures [6] .22
Figure 10 – Correlation of tensile elongation with modulus measurements made using
the modulus profiling apparatus for a CP jacket aged at the three indicated
temperatures (from Reference [8]) .23
Figure 11 – Correlation of tensile elongation with modulus measurements made using
the modulus profiling apparatus for a CSPE jacket aged at the four indicated combined
environments [9] .23
Figure 12 – Correlation of tensile elongation with NMR relaxation time measurements
for a CP jacket aged at the three indicated temperatures (from Reference [8]).24
Figure 13 – Correlation of tensile elongation with NMR relaxation time measurements
for a XLPO insulation aged at the two indicated temperatures [12].24
Figure 14 – Carbonyl absorbance as a function of the radiation dose for XLPE [15].25

TS 61244-3  IEC:2005(E) – 3 –
Figure 15 – Carbonyl absorbance as a function of thermal ageing for XLPE [14].25
Figure 16 – Correlation of tensile elongation with solvent uptake factor for a CP jacket
aged at the three indicated temperatures [8] .26
Figure 17 – Elongation results compared to uptake and gel results for XLPE insulation
aged at 130 °C [18].26
Figure 18 – Elongation results compared to uptake and gel results for an XLPO
insulation aged at 125 °C [18].27

Table 1 – Summary of currently available techniques for cable condition monitoring.15

– 4 – TS 61244-3  IEC:2005(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
LONG-TERM RADIATION AGEING IN POLYMERS –

Part 3: Procedures for in-service monitoring
of low-voltage cable materials

FOREWORD
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future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 61244-3, which is a technical specification, was prepared by subcommittee 15E: Methods
of test, of IEC technical committee 15: Insulating materials, which has now been merged with
IEC technical committee 98: Electrical insulation systems into IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems (provisional title).

TS 61244-3  IEC:2005(E) – 5 –
This second edition cancels and replaces the first edition, published in 1998, and constitutes
a technical revision. The main technical changes with regard to the previous edition are as
follows:
a) as there have been technical advances in established test methods and newer methods
have become available, several additions have been made to the techniques available in
Clause 5;
b) some of the techniques listed in the previous edition were found to be either unsuitable for
use as cable monitoring methods in plants, or less sensitive to radiation ageing than other
methods; these techniques have now been removed;
c) a list of abbreviations and their meanings has been added.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
15E/252/DTS 15E/258/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61244 consists of the following parts, under the general title Long-term radiation ageing
in polymers:
Part 1 Techniques for monitoring diffusion-limited oxidation
Part 2: Procedures for predicting ageing at low dose rates
Part 3: Procedures for in-service monitoring of low-voltage cable materials
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result dateindicated 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
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – TS 61244-3  IEC:2005(E)
INTRODUCTION
Polymers are widely used as e
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