DIN EN 60079-28:2016-04

This part of DIN EN 60079 (VDE 0170) specifies the requirements, testing and marking of equipment emitting optical radiation intended for use in explosive atmospheres. In revising this standard, the experience gained in practical application to date has been taken into account and translated into clarifications and assistance for the user. This standard contains requirements for devices with optical fibres and for optical devices including LED and laser devices with optical radiation in the wavelength range from 380 nm to 10 µm. For clarification purposes, the scope also lists devices to which this standard should not be applied (exclusion list). It covers the following ignition mechanisms: - Optical radiation is absorbed by surfaces or particles, causing them to heat up, and under certain circumstances this may allow them to attain a temperature which will ignite a surrounding explosive atmosphere. - In rare special cases, direct laser induced breakdown of the gas at the focus of a strong beam, producing plasma and a shock wave both eventually acting as ignition source. These processes can be supported by a solid material close to the breakdown point. The requirements apply to devices intended for use under atmospheric conditions. The responsible committee is DKE/K 241 "Schlagwetter- und explosionsgeschützte elektrische Betriebsmittel" ("Electrical apparatus for potentially explosive atmospheres") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.