IEC TR 62690:2014

Hydrogen effects in optical fibre cables - Guidelines

IEC TR 62690:2014 which is a technical report provides information concerning the behaviour of fibres and cables when exposed to hydrogen effects. The application of multimode fibres is very rarely subject to hydrogen effects. For that reason, this technical report only highlights the effects of hydrogen to single-mode fibres. Keywords: hydrogen effects, single-mode fibres

General Information

• Status: Published
• Publication Date: 18-Jun-2014
• ICS: 01.060 - Quantities and units
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: SC 86A - Fibres and cables
• Current Stage: PPUB - Publication issued
• Start Date: 19-Jun-2014
• Completion Date: 30-Sep-2014

Overview

IEC TR 62690:2014 - Hydrogen effects in optical fibre cables – Guidelines - is a technical report from the IEC that summarizes how hydrogen interacts with optical fibres and cable structures and offers guidance for evaluating hydrogen‑induced attenuation. The report focuses on single‑mode fibres, noting that multimode fibres are very rarely affected by hydrogen. It describes mechanisms of loss, measurement indicators, and when cable‑level evaluation is warranted.

Key topics

• Scope and focus: Guidance is targeted at single‑mode fibres and their behaviour when exposed to hydrogen during service life.
• Mechanisms of optical loss:
  • Reversible interstitial effect: Diffusion of H2 into silica glass causing attenuation that is roughly linear with hydrogen partial pressure.
  • Permanent chemical effect: Hydroxyl (OH) formation by chemical reaction with defect sites; magnitude scales approximately with the square root of partial pressure.
  • Wavelength‑dependent, temperature‑driven loss: Observed at elevated temperatures (above ~60 °C) and usually smaller than interstitial loss.
• Measurement and monitoring:
  • Monitoring attenuation at characteristic wavelengths (around 1 240 nm and 1 380 nm) is recommended as an indicator of both interstitial and permanent effects.
  • The report gives representative attenuation limits for single‑mode fibre (example: increases no greater than 0.03 dB/km at 1 310 nm and 0.06 dB/km at 1 550 nm under specified conditions).
• Factors influencing hydrogen effects:
  • Fibre dopant composition and intrinsic susceptibility
  • Hydrogen generation sources in cable (material outgassing, pressurised air, corrosion, microbiological action)
  • Cable construction and materials (presence of hermetic barriers, hydrogen‑absorbing materials)
  • Installation environment and operating temperature

Applications

IEC TR 62690 provides practical guidance for:

• Cable designers selecting materials and constructions to minimize hydrogen ingress.
• Fibre manufacturers understanding susceptibility of single‑mode designs.
• Test laboratories and qualification teams deciding when cable‑level hydrogen testing is necessary.
• Network planners and operators assessing long‑term attenuation risk in terrestrial, aerial, duct and shallow/underwater deployments.

The report also includes a decision guide (Table 1) to indicate when hydrogen evaluation is recommended based on cable type and environment.

Who should use this standard

• Optical fibre and cable designers
• Test and qualification engineers
• System integrators and installers for terrestrial and submarine links
• Standards developers and research teams studying long‑term fibre reliability

Related standards

• IEC 60794‑3, IEC 60794‑4, IEC 60794‑5 (optical fibre cable sectional specifications)
• ITU‑T L.27 (method for estimating hydrogen concentration in optical fibre cables)

Keywords: hydrogen effects, single‑mode fibres, hydrogen‑induced attenuation, optical fibre cables, IEC TR 62690

Standards Content (Sample)

IEC TR 62690 ®
Edition 1.0 2014-06
TECHNICAL
REPORT
colour
inside
Hydrogen effects in optical fibre cables – Guidelines

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IEC TR 62690 ®
Edition 1.0 2014-06
TECHNICAL
REPORT
colour
inside
Hydrogen effects in optical fibre cables – Guidelines

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
J
ICS 33.180.10 ISBN 978-2-8322-1657-6

– 2 – IEC TR 62690:2014 © IEC 2014
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 General . 6
4 Evaluation of hydrogen induced effects . 6
5 Hydrogen effects in optical fibre cables . 7
Bibliography . 9

Table 1 – Evaluation criteria for single-mode (SM) optical fibre cables . 7

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HYDROGEN EFFECTS IN OPTICAL FIBRE CABLES – GUIDELINES

FOREWORD
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example "state of the art".
IEC TR 62690, which is a technical report, has been prepared by subcommittee 86A: Fibres
and cables, of IEC technical committee 86: Fibre optics.
The text of this technical
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