CONTENTS

Introduction
Annex  A  –  Measurement of hydrogen released by each cable component by gas chromatography
        A.1     Principle
        A.2     Equipment
        A.3     Measurement procedures
        A.4     Analysis
Annex  B  –  Measurement of the concentration of hydrogen in a cable sample
        B.1     Unfilled cable
        B.2     Filled cable
Annex  C  –  Measurement of the long-term effectiveness of hydrogen-absorbing materials
        C.1     Principle
        C.2     Apparatus
        C.3     Measurement procedures
        C.4     Analysis
Appendix  I  –  UK experience of hydrogen concentrations in moisture barrier optical fibre duct cables
        I.1     Field experience
        I.2     Analysis
        I.3     References
Appendix  II  –  Japanese experience of the loss increase due to hydrogen generation in water-blocking tape  optical fibre cable
       II.1     Structure and materials of the water-blocking tape cable
       II.2     Hydrogen generated from cable components
       II.3     Evaluation of loss increase due to hydrogen generation
       II.4     Increase in loss in water-penetrated cable
Appendix  III  –  Spanish experience of hydrogen generation in moisture barrier optical fibre cables
      III.1     Cable structure
      III.2     Field experience
      III.3     Origin of the problem
      III.4     Problem solution