2. Installation
2.3 Ex survey according
to Directive 94/9/EC
(ATEX)
Applies to instruments used in underground mining
operations, as well as their above ground operations,
which can be endangered by mine gas and/or
flammable dusts.
Instrument groups
Applies to instruments used in the remaining areas
which can be endangered by a potentially explosive
atmosphere.
Instruments of this category are for use in areas
where ignitable atmospheres caused, by a mixture
of air and gasses, vapours or mists or by dust/
air mixtures, can exist all of the time or for long
periods of time or else frequently.
Instruments of this category are for use in areas
where ignitable atmospheres caused, by a mixture
of air and gasses, vapours or mists or by dust/air
mixtures, can exist some of the time.
Instruments of this category are for use in areas
where ignitable atmospheres caused, by a mixture
of air and gasses, vapours or mists or by dust/air
mixtures, are not likely to exist. However, if they
do occur then in all probability, only seldom or for
short periods of time.
Instrument category
(TheguresinbracketsrefertoIEC)
Explosion protected electrial equipment = Ex
Ex protection labelling in square brackets refers to "Associated electrical equipment"
as an example: II 2G Ex ia IIC T5
Type of protection
o Oil encapsulated i Intrinsic safety (ia, ib)
p Pressurizedapparatus n Non-incentiveequipment
q Powderlling m Encapsulation
d Flameproof enclosure s Special protection
e Increased safety
Explosion groups
Gases and vapours Minimum EN/
(examples) ignition IEC
energy [mJ]
•Ammonia - IIA
• Acetone,aircraftfuel,benzine,
crude oil, diesel oil, ethane, ethanoic
acid, ether, gasolines, heating oil,
hexane, methane, propane 0.18 IIA
•Ethylene, isoprene, town gas 0.06 IIB
•Acetylene, carbon disulphide,
hydrogen 0.02 IIC
Ignition temperature
Maximum surface temperature EN / IEC
450°C 842°F T1
300°C 572°F T2
200°C 392°F T3
135°C 275°F T4
100°C 212°F T5
I
II
EN 50014 Directive 94/9/EC (ATEX)
Denition
1G
(0)
Labelling
with gases
Labelling
with dusts
1D
(20)
2G
(1)
2D
(21)
3G
(2)
3D
(22)