3
Hazardous area classifications:
Zone 0:
An area classified as Zone 0 will have ignitable concentrations
of flammable gases, vapours or liquids either continuously
present or present for long periods of time under normal
operating conditions. Intrinsically Safe (Exia) detectors are
suitable for use in Zone 0, provided they are connected via a
suitable zener barrier or galvanic isolator.
Zone 1:
An area classified as Zone 1 is likely to have ignitable
concentrations of flammable gases, vapours or liquids present
under normal operating conditions. Flameproof (Exd) detectors
are suitable for use in Zone 1. Intrinsically Safe (Exia) detectors
are suitable for use in Zone 1, provided they are connected via
a suitable zener barrier or galvanic isolator.
Zone 2:
An area classified as Zone 2 is not likely to have ignitable
concentrations of flammable gases, vapours or liquids present
under normal operating conditions. Flameproof (Exd) detectors
are suitable for use in Zone 2. Intrinsically Safe (Exia) detectors
are suitable for use in Zone 2, provided they are connected via
a suitable zener barrier or galvanic isolator.
Notes:
In North America ‘Divisions’ are used to categorise risk where:
Division 1 is equivalent to Zone 0 or 1
Division 2 is equivalent to Zone 2
Under European ATEX rules hazardous area equipment has been
redefined under ‘equipment categories’ where:
Equipment Category 1 is suitable for Zone 0
Equipment Category 2 is suitable for Zone 1
Equipment Category 3 is suitable for Zone 2
Safety information