ATEX / Ex Marking Decoder

Enter a full ATEX/Ex marking (e.g. II 2 G Ex db IIB T4 Gb) and get a line-by-line breakdown — equipment group, category, atmosphere, protection modes, gas group, temperature class, EPL — with an automatic category↔EPL coherence check.

Summary — where can it be installed? —

Equipment group —

ATEX category —

Atmosphere type —

Protection mode —

Physical protection principle —

Gas / dust group —

Temperature class —

EPL (Equipment Protection Level) —

Category ↔ EPL coherence —

Formule

STRUCTURE OF AN ATEX / Ex MARKING

  [Group] [Category] [Atmosphere]  Ex [Mode] [Gas group] [Temp class] [EPL]

  Variables :
    Group         I (mines) or II (surface) — ATEX Directive
    Category      1 / 2 / 3 (or M1 / M2 for Group I)
    Atmosphere    G (gas) or D (dust) or GD (both)
    Mode          d / e / i / p / n / m / q / o / t — IEC 60079
    Gas group     IIA / IIB / IIC (gas) or IIIA / IIIB / IIIC (dust)
    Temp class    T1 (450°C) → T6 (85°C) — max surface temperature
    EPL           Ga / Gb / Gc (gas) or Da / Db / Dc (dust)

  Rationale : the compact Ex marking carries every condition of use
  for a piece of equipment. Decoding it is essential to verify that
  a device matches the actual installation zone.


CATEGORY ↔ ZONE ↔ EPL MAPPING

  Category 1G  ↔  Zone 0   ↔  EPL Ga      (explosive atmosphere continuously present)
  Category 2G  ↔  Zone 1   ↔  EPL Gb      (likely during normal operation)
  Category 3G  ↔  Zone 2   ↔  EPL Gc      (unlikely or short duration)
  Category 1D  ↔  Zone 20  ↔  EPL Da
  Category 2D  ↔  Zone 21  ↔  EPL Db
  Category 3D  ↔  Zone 22  ↔  EPL Dc

  Rationale : Category and EPL must be consistent. A Category 2
  device can only be marked Gb (gas) or Db (dust), never Ga or Gc.
  This decoder flags inconsistencies automatically.


SUPPORTED MARKING VARIANTS

  Classic with spaces:           II 2 G Ex db IIB T4 Gb
  Compact (Pepperl, ABB):        II 1G Ex ia IIC T6 Ga
  Mixed:                          II2G Ex db IIB T4 Gb
  Zone 0/1 boundary:             II 1/2 G Ex ia IIC T4 Ga/Gb
  Multiple modes:                 II 2 G Ex de IIC T4 Gb
  New ec mode (zone 2):          II 3 G Ex ec IIC T4 Gc
  Dust with explicit temp:       II 2 D Ex tb IIIC T135°C Db
  Combined gas + dust:           II 2 GD Ex db IIC T4 Gb
  IECEx without ATEX prefix:     Ex db IIC T4 Gb
  Mining:                         I M2 Ex db I Mb
  Associated apparatus:          II (2) G Ex ib IIB T4 Gb
  With Ta range (tolerated):     II 2 G Ex ib IIC T4 Gb -40°C ≤ Ta ≤ +60°C

  The decoder normalizes spacing, accepts varied token orders, and
  remains tolerant to manufacturer variations.

Reference: Directive 2014/34/EU, IEC 60079-0

The Ex marking of an ATEX-rated piece of equipment is dense: it combines the European regulatory frame (Directive 2014/34/EU) and the international technical marking (IEC 60079) in a single compact line. To verify that a sensor, motor or junction box is fit for a given zone, you need to read every part of the marking.

How to use:

Enter the full marking exactly as it appears on the nameplate (spaces matter).
The decoder identifies each part and explains it in plain language.
The verdict automatically checks that the ATEX Category and the EPL letter are consistent — an inconsistency signals a suspicious nameplate or a labelling error.

Important: the Ex marking describes what the equipment is capable of, not what your installation requires. Final compliance rests on the zone classification (IEC 60079-10-1 for gas, 60079-10-2 for dust) and the selection of equipment of a category at least equal to the zone’s requirements.

ATEX / Ex Marking Decoder

ATEX / Ex Marking Decoder

Standards