What are two common types of smoke detectors?

What are two common types of smoke detectors?

• A. Ionization and Photo-Electric
• B. Ionization and Heat
• C. Photo-Electric and CO
• D. Smoke Detectors and Heat

Answer: (A)

Two common smoke detector technologies are ionization and photoelectric. Ionization detectors use a tiny radioactive source to create ionized air between two plates; when smoke enters, the ions are neutralized and the current drops, triggering the alarm. They’re particularly quick for flaming fires with fast, small smoke particles. Photoelectric detectors use a light beam and a sensor; when smoke enters, it scatters the light toward the sensor and the alarm goes off, making them especially responsive to smoldering fires with larger smoke particles. Some detectors combine both technologies in one unit to improve overall sensitivity. Note that heat detectors and carbon monoxide detectors are different kinds of devices and aren’t smoke detectors.

Two common smoke detector technologies are ionization and photoelectric. Ionization detectors use a tiny radioactive source to create ionized air between two plates; when smoke enters, the ions are neutralized and the current drops, triggering the alarm. They’re particularly quick for flaming fires with fast, small smoke particles. Photoelectric detectors use a light beam and a sensor; when smoke enters, it scatters the light toward the sensor and the alarm goes off, making them especially responsive to smoldering fires with larger smoke particles. Some detectors combine both technologies in one unit to improve overall sensitivity. Note that heat detectors and carbon monoxide detectors are different kinds of devices and aren’t smoke detectors.