How do intrinsic safety barriers work for hazardous area signal conditioning?

Intrinsic safety (IS) barriers limit energy to field devices in hazardous areas below ignition threshold. Zener barrier: uses Zener diodes to clamp voltage, resistor to limit current, fuse for fault protection, requires IS ground connection. Galvanic isolator: provides electrical isolation plus energy limiting, no IS ground required, better protection and easier installation. Selection: specify barrier based on cable parameters (capacitance, inductance), device requirements, and entity concept calculations. Documentation: match barrier and device parameters per IEC/EN 60079-14. Barriers must be mounted in safe area with proper installation practices.