What is an ionized smoke detector?

An ionized smoke detector uses a small amount of radioactive material, typically americium-241, to ionize air in a sensing chamber. This process creates a current that flows between two electrodes. When smoke enters the chamber, it disrupts this current, triggering the alarm. Ionized smoke detectors are particularly sensitive to fast-burning, flaming fires but may be less effective with smoldering fires compared to photoelectric smoke detectors.