Which detector detects smoke by ionization of air?

Prepare for the First Responder Inspector Test. Utilize sample tests, detailed explanations, and interactive flashcards to boost your confidence and knowledge. Get exam-ready!

Smell the smoke first by how the detector actually senses it: ionization detectors use a small amount of radioactive material to ionize the air inside a sensing chamber, creating a steady current between two charged plates. When smoke particles enter, they attach to the ions, reducing the current and triggering the alarm. This direct use of ionized air is what sets this type apart from the others. In contrast, photoelectric detectors rely on light—either scattering light off smoke particles or having smoke block a light beam—or air-sampling detectors pull air into a chamber to analyze particles, none of which depend on ionizing the air itself. So the method of detecting smoke by ionizing the air is unique to ionization detectors.