EN 60079-20-1:2010

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Classification of gases and vapours
5 Data for flammable gases and vapours, relating to the
  use of equipment
6 Method of test for the maximum experimental safe gap
7 Method of test for auto-ignition temperature
Annex A (normative) - Furnaces of test apparatus for the
        tests of auto-ignition temperature
Annex B (informative) - Tabulated values
Bibliography
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications
Annex ZZ (informative) - Coverage of Essential Requirements
         of EC Directives

IEC 60079-20-1:2010 provides guidance on classification of gases and vapours. It describes a test method intended for the measurement of the maximum experimental safe gaps (MESG) for gas- or vapour-air mixtures under normal conditions of temperature and pressure so as to permit the selection of an appropriate group of equipment. The tabulated values of chemical and engineering properties of substances are provided to assist engineers in their selection of equipment to be used in hazardous areas. This first edition of IEC 60079-20-1 cancels and replaces the first edition of IEC 60079-1-1(2002), the second edition of IEC 60079-4 (1975), its amendment 1(1995) and its complement: IEC 60079-4A (1970), the first edition of IEC/TR 60079-12 (1978) and the first edition of IEC 60079-20 (1996). It constitutes a technical revision.