This coding indicates that the equipment is certified for use in Hazardous Areas. Each symbol specifies a distinct protection method and safety integrity level:
- Ex: Indicates Explosion Protection; the equipment is designed, tested, and certified for operation in explosive atmospheres.
- db: Flameproof Enclosure protection (Level 'b' – High Protection), designed to contain an internal explosion and prevent flame propagation.
- eb: Increased Safety protection, utilizing measures to prevent arcs, sparks, or excessive temperatures during normal or specified abnormal conditions.
- ia: Intrinsic Safety (Level 'a' – Highest Protection), ensuring electrical energy is limited below ignition levels even under two-fault conditions.
- [ia Ga]: An Intrinsically Safe associated apparatus with an 'ia' output, suitable for interfacing with devices located in Zone 0 (EPL Ga).
- mb: Encapsulation protection; components are embedded in resin to isolate them from the explosive atmosphere.
- [op is]: Inherently Safe Optical Radiation; limits the energy of light or laser beams to prevent ignition of the surrounding atmosphere.
- op pr: Protected Optical Radiation; protection by enclosing the optical beam to prevent radiation leakage into the hazardous area.
- IIC: Gas Group IIC; indicates suitability for the most volatile gases, such as Hydrogen and Acetylene.
- T6…T4: Temperature Class; a guarantee that the maximum equipment surface temperature will not exceed:
- T6 = 85°C
- T5 = 100°C
- T4 = 135°C
- Gb: Equipment Protection Level (EPL); rated for high protection, suitable for use in Zone 1.