UNE-EN 60079-28:2016

INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
  4.1 Optical equipment
  4.2 Risk levels
5 Types of protection
  5.1 General
  5.2 Requirements for inherently safe optical radiation
       'op is'
  5.3 Requirements for protected optical radiation 'op pr'
  5.4 Optical radiation interlock with optical fibre breakage
       'op sh'
  5.5 Suitability of types of protection
6 Type verifications and tests
  6.1 Test set-up for ignition tests
  6.2 Reference test
  6.3 Test mixtures
  6.4 Tests for pulse trains and pulses between 1 ms and
       1 s duration
7 Marking
  7.1 General
  7.2 Marking information
  7.3 Examples of marking
Annex A (normative) - Reference test data
Annex B (informative) - Ignition mechanisms
Annex C (normative) - Ignition hazard assessment
Annex D (informative) - Typical optical fibre cable design
Annex E (informative) - Introduction of an alternative risk
        assessment method encompassing 'equipment protection
        levels' for Ex equipment
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications
Annex ZZ (informative) - Coverage of Essential Requirements
         of EC Directives
Bibliography

Describes the potential ignition hazard from equipment using optical radiation intended for use in explosive gas atmospheres. Also covers equipment, which itself is located outside but its emitted optical radiation enters such atmospheres.