Which detection device uses radioactive material within the device to help in activating the device?

Which detection device uses radioactive material within the device to help in activating the device?

• A. Photoelectric smoke detector
• B. Ionization smoke detector
• C. Pull station
• D. Heat detector

Answer: (B)

Ionization smoke detectors rely on a tiny radioactive source inside the unit. This source ionizes the air in the sensing chamber, creating a steady electrical current between two plates. When smoke particles enter the chamber, they attach to the ions, reducing the current and triggering the alarm. The radioactive material, usually americium-241, is sealed and poses minimal risk because it stays contained inside the detector. The other options don’t use radioactive material: a photoelectric detector uses a light beam and a sensor to detect smoke through light scattering, a heat detector responds to a rapid rise in temperature, and a pull station is a manual alarm device.

Ionization smoke detectors rely on a tiny radioactive source inside the unit. This source ionizes the air in the sensing chamber, creating a steady electrical current between two plates. When smoke particles enter the chamber, they attach to the ions, reducing the current and triggering the alarm. The radioactive material, usually americium-241, is sealed and poses minimal risk because it stays contained inside the detector. The other options don’t use radioactive material: a photoelectric detector uses a light beam and a sensor to detect smoke through light scattering, a heat detector responds to a rapid rise in temperature, and a pull station is a manual alarm device.