November 18, 2016
Ask the Inspector: Smoke detectors
Q: I have heard of two different kinds of smoke detectors. What are they and which one is better?
A: There are two different types of smoke detectors:
1. Photoelectric Detector. This device a light and a light sensor. When smoke enters the detector, the sensor senses that the light beam has been disrupted and sets off an alarm.
2. Ionization Detector. This one has an ionization chamber where particles are charged using a small amount of radioactive material. When smoke enters the chamber, the detector senses the change in the current and sets off the alarm.
So, which one is best?
Both types of detectors will detect all types of fires. However, the photoelectric detectors appear to sense smoldering fires better, while the ionization detectors seem to sense flaming fires better.
Fire departments are recommending that you install smoke detectors with both types of sensors, either in one unit or two separate units.
For more information, download the Ask the Inspector flyer (PDF).