Explanation of ATEX Markings

ATEX is derived from ATmosphères EXplosibles and refers to the EU directive 2014/34/EU, which deals with equipment and protective systems used in potentially explosive atmospheres. The objectives are to prevent hazards and protect the health and safety of persons using these devices and protective systems.

Up-to-date ATEX markings help you to quickly and conveniently catch up on the various applications, protection concepts, equipment groups, and temperature classes of our ATEX load cells.

ATEX Directive 2014/34/EU

In April 2016, the European Commission published the ATEX Directive 2014/34/EU, which replaced Directive 94/9/EC.

It meant little change for the manufacturers of explosion-protected equipment, as the essential health and safety requirements for explosion-protected equipment remain unchanged and all certificates issued under the old ATEX Directive 94/9/EC remain valid without any further changes. The harmonised EN600xx standards will also continue to apply under the new Directive and the conformity assessment procedures will remain the same.
 

Extended Scope

The ATEX Directive 2014/34/EU extends the circle of economic operators by clarifying the concept of ‚making available on the market’. Besides ‚manufacturers’ or those ‚placing a product on the market’, the new definition also refers to importers and distributors, as well as to all operators who manufacture explosion-protected equipment from components or sub-assemblies for their companies.

ATEX markings at a glance

As components such as sensors and load cells are also covered by the ATEX directive, we would like to give you an overview of the various markings on this page. Based on the current ATEX markings, you can quickly and conveniently find information on the respective application areas, safety concepts, equipment groups and temperature classes.

Download the ATEX poster (PDF)

TYPES OF PROTECTION FOR ELECTRICAL EQUIPMENT IN EXPLOSIVE ATMOSPHERES

Degree of protection Symbol Zone Depiction Main application Standard
General requirements         IEC 60079-0
EN 60079-0
UL 60079-0
Increased safety

e,eb,
ec

1
2

Terminals and junction boxes, control cabinets for installation of Ex components
(which have a different type of protection), cage rotor motors, light fittings

IEC 60079-7
EN 60079-7
UL 60079-7

Flameproof enclosure

da
d, db
dc

0
1
2

Switchgears, switch devices and systems, control stations, display devices, indicating
equipment,control systems, motors, transformers, heating devices, light fittings

IEC 60079-1
EN 60079-1
UL 60079-1

Pressurization

px, pxb
py, pxb
pz, pzc

1 21
1 21
2 22

Switching and control cabinets, analysis devices, large motors

 

IEC 60079-2
EN 60079-2
UL 60079-2

Intrinsic safety

ia
ib
ic

0
1
2

Measurement and regulation systems, fieldbus systems, sensors, actuators
[Ex ib] = Related electrical equipment – installation in the safe area

IEC 60079-11
EN 60079-11
UL 60079-11

         

IEC 60079-25
EN 60079-25
UL 60079-25

Oil immersion

o, ob
oc

1
2

Transformers, starting resistors

IEC 60079-6
EN 60079-6
UL 60079-6

Powder filling q, qb 1 Sensors, indicators, electronic ballasts, transmitters IEC 60079-5
EN 60079-5
UL 60079-5
Encapsulation

ma
mb
mc

0 20
1 21
2 22

Switch devices for low output levels, command and signaling devices,
indicators, sensors
IEC 60079-18
EN 60079-18
UL 60079-18
Type of protection "n"

nA, nAc
nC, nCc
nR, nRc

2
2
2

All electrical equipment for Zone:
2 nA = non-sparking equipment
nC = sparking equipment in which the contacts are protected in some suitable way
nR = restricted breathing enclosures

IEC 60079-15
EN 60079-15
UL 60079-15
Optical radiation

op_, op_a
op_, op_b
op_, op_c

0 20
1 21
2 22

op is = intrinsically safe optical radiation
op pr = protected optical radiation
op sh = shielded optical radiation

IEC 60079-28
EN 60079-28
UL 60079-28
Protection by enclosure

ta
tb
tc

20
21
22

Switch devices and systems, control cabinets, junction and terminal boxes,
motors, lights

IEC 60079-31
EN  60079-31
UL  60079-31

 

EQUIPMENT CATEGORY AND EQUIPMENT PROTECTION LEVEL

Acc. to EU directive 2014/34/EU (ATEX)

Acc. to IEC and CENELEC  
Equipment group Equipment category EPL

Adequate safety

Underground parts of mines likely to be endangered by firedamp

I

M1 Ma

With rare errors

I M2 Mb

Until the device is turned off

Explosive gas atmospheres

II 1G Ga

Zone 0       With rare errors

II 2G Gb

Zone 1       With foreseeable errors

II 3G Gc

Zone 2       In normal operation

Atmospheres with combustible dust

II 1D Da

Zone 20     With rare errors

II 2D Db

Zone 21     With foreseeable errors

II 3D Dc

Zone 22     In normal operation

(1)G Related electrical equipment – installation in the safe area

 

  ELECTRONIC DEVICES
ATEX

II (1) 2G

Ex             d [ia Ga]              IIC

T4

Gb*

IECEx  

Ex             d [ia Ga]              IIC

T4

Gb*

NEC 500

       

NEC 505

 

I (1) 1A

T4

 

NEC 506

       
 

*If the alternative symbols are used, the EPL can be omitted.

 

GROUPS

IEC / CENELEC / NEC 505 / NEC 506

NEC 500

Group I

Underground parts of mines likely to be endangered by firedamp
 

Methane

   

Group II

Subgroups

Explosive gas atmospheres:

Typical gas

Class I

Subgroups

IIA

Propane

Propane

Class I Group D

IIB

Ethylene

Ethylene

Class I Group C

IIC Hydrogen Hydrogen Class I Group B
 

Acetylene

Acetylene

Class I Group A

Group III

Subgroups

Atmospheres with combustible dust

Type of dust

Class II / III

Subgroups
IIIA

Combustible lint

Fibers and lint

Class III

IIIB

Non-conductive dust

Non-conductive dust

Class II Group G

IIIC

Conductive dust

Carbonaceous dust

Class II Group F

Combustible metal dust

Class II Group E

 

      TEMPERATURE CLASSIFICATION

Maximum surface
temperature

 Gas temperature classes 

Maximum surface
temperature

Gas temperature classes  

Device marking

Device marking

NEC 500

CENELEC / IEC /NEC 505

NEC 500

CENELEC / IEC /NEC 505

450°C T1 T1 200°C T3  
300°C T2 T2 180°C T3A  
280°C T2A   165°C T3B  
260°C T2B   160°C T3C  
230°C T2C   135°C T4 T4
215°C

T2D

  120°C T4A  

Dust: maximum surface temperature specified in °C

100°C T5 T5
85°C T6 T6

 

ZONES

Hazardous explosive atmosphere
 

Continuously, frequently or long-term

Occasionally

 Rarely and briefly

Gas

CENELEC/IEC/NEC 505

Zone 0 

Zone 1

Zone 2

NEC 506 (Class I)

Division 1

Division 2
Dust CENELEC/IEC/NEC 505 Zone 20 Zone 21 Zone 22

NEC 506 (Class II, III)

Division 1

Division 2

 

The following HBM products are available in certified ATEX versions

*Beam and RTN load cells also have EAC conformity. If you would like to find out about HBK products and EAC markings, or if you have have additional questions concerning ATEX, please contact us

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