arpadveress 
To document the classification of potentially explosive atmospheres into an explosive zone a zone classification documentation is provided.
The zone classification documentation shall include (with details as appropriate):
(a) design limits;
(b) a brief description of the technology envisaged,
(c) a description of the risk of explosion,
(d) a description of the material properties relevant for explosion protection.
The classification of a zone shall be made in accordance with a legal requirement, a relevant technical requirement (eg a standard) or industry practice, of which written and, where necessary for understanding, multi-point drawing of the zone shall be prepared.
The completed zone classification shall be supported by technical justification (if necessary by calculation).
At least a skilled technician should be involved in the preparation of the zone classification documentation.
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