What are the two main types of smoke detectors?

The two main types of smoke detectors are ionization and photoelectric smoke detectors.

Ionization smoke detectors work by using a small amount of radioactive material to ionize the air in the sensing chamber. This creates a small current that flows between two metal plates. When smoke enters the chamber, it disrupts this ionization process, leading to a decrease in current flow and triggering the alarm. These detectors are particularly effective at detecting fast-burning fires that produce small combustion particles.

Photoelectric smoke detectors operate differently. They use a light source and a light sensor positioned at an angle within the detector's chamber. When smoke enters the chamber, it scatters the light beam, directing it towards the sensor and triggering the alarm. Photoelectric detectors are more effective at detecting smoldering fires that produce larger particles, which are common in many residential fires.

Together, these technologies offer comprehensive fire detection capabilities, as they are sensitive to different types of fire conditions, enhancing overall safety in environments where they are installed.