Ohio Volunteer Firefighter Practice Exam 2025 – The All-in-One Guide to Exam Success!

The type of smoke detector that uses a light beam to detect smoke is a beam detector. These detectors operate by projecting a beam of light across an area to a receiver. When smoke enters the beam path, it scatters the light and reduces the intensity received at the detector, triggering an alarm. This makes beam detectors particularly effective in large open spaces, such as warehouses or auditoriums, where traditional point detectors may not be as effective.

In contrast, other types of smoke detectors function differently. Photoelectric detectors use a light source and a sensor in a chamber where smoke particles disrupt the light, but they do not utilize a beam across an area; rather, they often rely on the change in light intensity within their housing. Ionization detectors detect smoke through the disruption of ions in the air but do so without using a light beam. Thermal detectors respond to changes in temperature rather than detecting smoke particles, making them ineffective for identifying smoke presence in the same way beam detectors do.