An Intrinsically Safe (IS) barrier is a protective interface used in hazardous industrial areas to limit voltage and current, ensuring that electrical signals cannot ignite flammable gases or dust. IS barriers come in two main types: Zener barriers, which use diodes and grounding to restrict energy, and galvanic isolation barriers, which provide safer, ground‑free isolation between field devices and control systems. They are widely used with sensors, transmitters, and communication loops. Well‑known IS barrier brands include Pepperl+Fuchs, PR Electronics, MTL (Eaton), GM International, Phoenix Contact, Turck, and R. Stahl, all trusted for explosion‑proof automation applications.