Reaffirmed 2022

NATIONAL FOREWORD

This Indian Standard (Part 1/Sec 20) (First Revision) which is identical with IEC 60793-1-20 : 2014 ‘Optical fibres - Part 1-20 : Measurement methods and test procedures - Fibre geometry’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on recommendation of the Fibre Optics, Fibres, Cables and Devices Sectional Committee and approvalof the Electronics and Information Technology Division Council.

This standard was originally published in 2009 and was based on IEC 60793-1-20 : 2001. The first revision of this standard has been undertaken to align it with the latest version of IEC 60793-1-20 : 2014.

The text of IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.