The typical smoke alarm available from your corner hardware store is what's called an ionization detector. They generate a small electrical current flow within the detector's sensing chamber. Smoke particles entering this chamber impede the flow of ions, and thus the current flow, which in turn causes the detector's alarm to sound.
Gentex detectors are photoelectric. They use a light emitting diode (LED) to produce a continual beam of light that spans the detector's sensing chamber. Smoke particles entering the chamber refract the light onto a light sensor, which in turn sound the detector's alarm.
Again, photoelectric detectors have become the products of choice for commercial applications because they're less prone to false alarms and are quick to detect slow, smoldering fires.
|
