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ATEX Marking Decoder — Read Any Ex Certificate or Label
ATEX and IECEx markings encode all the critical information about Ex equipment — where it can be used, what gas groups it's rated for, its temperature class, and its Equipment Protection Level. This decoder explains every element.
Example Markings — Decoded
⑥ II 2 G Ex d IIB T4 Gb
| Element | Value | Meaning |
|---|---|---|
| ⑥ | ATEX symbol | ATEX certified equipment |
| II | Group II | Surface industries (not mining) |
| 2 | Category 2 | Zone 1 suitability (or Zone 2) |
| G | Gas | Gas explosive atmosphere |
| Ex | Ex protected | Certified to IEC 60079 |
| d | Flameproof | Ex d protection type — IEC 60079-1 |
| IIB | Gas group IIB | Suitable for IIA and IIB gas groups |
| T4 | Temperature class | Maximum surface temperature 135°C |
| Gb | EPL Gb | Suitable for Zone 1 and Zone 2 |
⑥ II 1 G Ex ia IIC T5 Ga
| Element | Value | Meaning |
|---|---|---|
| II 1 G | Category 1, Gas | Zone 0 suitable, gas atmosphere |
| Ex ia | Intrinsic safety ia | Highest IS grade — 2 faults safe |
| IIC | Gas group IIC | Suitable for any gas group |
| T5 | Temperature class T5 | Maximum surface temperature 100°C |
| Ga | EPL Ga | Suitable for Zone 0, 1, and 2 |
Protection Type Codes
d = flameproof · e = increased safety · i = intrinsic safety · ia = intrinsic safety (highest) · ib = intrinsic safety · ic = Zone 2 IS · p = pressurisation · t = dust protection · n = non-sparking · ec = energy-limited · m = encapsulation · o = oil immersion
Verification Checklist
When verifying an installed equipment marking against the area classification:
- EPL must be appropriate for the zone (Ga for Zone 0, Gb for Zone 1+, Gc for Zone 2 only)
- Gas group must match or exceed area gas group (IIC can go anywhere; IIA only in IIA areas)
- T-class maximum surface temperature must be less than gas AIT
- Certificate must be current (not expired or superseded)
Put This Into Practice
Interactive inspection simulations, equipment selection decisions, and 1,185+ practice questions referenced to IEC 60079. Try free — no card required.
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