Smoke detectors have become a staple in all homes. We have grown accustomed to seeing those small, round, plastic “decorations” on the walls or ceilings in most rooms in a home. Despite being commonplace in most homes, these small devices are not only out-of-date aesthetically, but do not provide the same type of fire and smoke protection that we expect them to.

The majority of smoke alarms in homes sense smoke and fire using ionization technology. When a fire breaks out, it produces electrically charged, or ionized, particles. These particles in the air float into the smoke detector’s ionization chamber. In the ionization chamber are two plates at opposite sides with a voltage across them, and a small amount of the radioactive element americium-241. The americium-241 generates alpha particles in the chamber that “ionize” oxygen and nitrogen. This causes a small electrical current in the chamber that the detector recognizes as normal. When ionized smoke particles enter the chamber, they attract ions in the chamber and disrupt the electrical current. When this happens, the horn sounds. Continue reading →