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.
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, | 1 |  | Terminals and junction boxes, control cabinets for installation of Ex components | IEC 60079-7 |
| Flameproof enclosure | da | 0 |  | Switchgears, switch devices and systems, control stations, display devices, indicating equipment,control systems, motors, transformers, heating devices, light fittings | IEC 60079-1 |
| Pressurization | px, pxb | 1 21 |  | Switching and control cabinets, analysis devices, large motors
| IEC 60079-2 |
| Intrinsic safety | ia | 0 |  | Measurement and regulation systems, fieldbus systems, sensors, actuators | IEC 60079-11 |
IEC 60079-25 | |||||
| Oil immersion | o, ob | 1 |  | Transformers, starting resistors | IEC 60079-6 |
| Powder filling | q, qb | 1 |  | Sensors, indicators, electronic ballasts, transmitters | IEC 60079-5 EN 60079-5 UL 60079-5 |
| Encapsulation | ma | 0 20 |  | 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 | 2 |  | All electrical equipment for Zone: | IEC 60079-15 EN 60079-15 UL 60079-15 |
| Optical radiation | op_, op_a | 0 20 |  | op is = intrinsically safe optical radiation | IEC 60079-28 EN 60079-28 UL 60079-28 |
| Protection by enclosure | ta | 20 |  | Switch devices and systems, control cabinets, junction and terminal boxes, motors, lights | IEC 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 | Gas temperature classes | Maximum surface | 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.
