This document gives guidance on the selection, installation, use and maintenance of electrically operated Group II apparatus intended for use in industrial and commercial safety applications for the detection and measurement of:
·combustible gases, as described in EN 50054, EN 50057, EN 50058; or
·oxygen as described in EN 50104.
This guide is a compilation of practical knowledge to assist the user. Combustible gas detection apparatus, fixed, transportable or portable, may be used whenever there is the possibility of a risk to life or property caused by the accumulation of a combustible gas-air mixture. Such apparatus can provide a means of reducing the risk by detecting the presence of the combustible gas and issuing suitable audible or visual warnings. It may also be used to initiate specific safety precautions (e.g. plant shutdown, evacuation, operation of fire extinguishing procedures).
It is applicable to all new permanent installations and, where reasonably practicable, to existing permanent installations. It is also applicable to temporary installations, whether new or existing.
This guide is not intended, but may provide useful information, for the following:
·apparatus intended for the measurement of oxygen deficiency which may affect human health;
·apparatus intended only for the detection of non-combustible toxic gases;
·apparatus of laboratory or scientific type intended only for analysis or measurement purposes;
·apparatus intended for underground mining applications;
·apparatus intended only for process control applications.
This guide does not apply to the following:
·apparatus for the detection of explosives;
·apparatus intended for the detection of a potentially combustible atmosphere resulting from dust or mist in air;
·open path apparatus not used for point measurement.
note:1) Group II apparatus are suitable for places with potentially explosive atmospheres, other than mines susceptible to firedamp, see 4.3.
2) For the purpose of this guide, "toxic" covers "toxic", "very toxic" and "harmful" gases and vapours.
BS EN 50073:1999 history
2015BS EN 60079-29-2:2015 Explosive atmospheres. Gas detectors. Selection, installation, use and maintenance of detectors for flammable gases and oxygen
2008BS EN 60079-29-2:2007 Explosive atmospheres - Part 29-2: Gas detectors - Selection, installation, use and maintenance of detectors for flammable gases and oxygen
1999BS EN 50073:1999 Guide for selection, installation, use and maintenance of apparatus for the detection and measurement of combustible gases or oxygen