What is a self-luminous exit sign?
A self-luminous exit sign is a non-electrical product that uses radioactive tritium gas to produce light. Specifically, the signs contain light sources that consist of glass tubes, internally coated with phosphor, and filled with tritium gas. Tritium (H-3) is an isotope of hydrogen that emits low-energy beta radiation in the form of electrons. These electrons excite the phosphor, causing the glass tubes to continuously emit light.
