NATIONAL FOREWORD

This Indian Standard (Part 18) (Second Revision) which is identical with IEC 60079-18 : 2014 ‘Explosive atmospheres — Part 18: Equipment protection by encapsulation “m”’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on the recommendation of the Electrical Apparatus for Explosive Atmospheres Sectional Committee and approval of the Electrotechnical Division Council.

This standard was first published as IS/IEC 60079-18 : 2004 which superseded IS 15451 : 2004 ‘Electrical apparatus for explosive gas atmospheres — Encapsulation ‘‘m’’ electrical apparatus’. The first revision of this standard was published in 2012 as IS/IEC 60079-18 : 2009 ‘Explosive atmospheres : Part 18 Equipment protection by encapsulation ‘‘m’’ (first revision)’. The second revision of this standard has been undertaken to align it with the latest version of IEC 60079-18.

The text of IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain 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.