What are the 2 types of fire alarms?

There are primarily two main types of fire alarms or fire detection systems commonly used:

1. Ionization Smoke Alarms:

  - Ionization smoke alarms are designed to detect fast-burning, flaming fires. They contain a small amount of radioactive material (americium-241) that ionizes the air within the smoke alarm's chamber.

  - When smoke enters the chamber, it disrupts the ionization process, causing a drop in the electrical current flow. This change triggers the alarm to sound, alerting occupants of the presence of smoke or fire.

  - These alarms are particularly sensitive to smaller smoke particles produced by fast, flaming fires.

2. Photoelectric Smoke Alarms:

  - Photoelectric smoke alarms are designed to detect slow-smoldering fires that produce larger smoke particles before the presence of flames.

  - They contain a light source (typically an LED) and a light-sensitive sensor. When smoke enters the alarm's chamber, it scatters the light, causing it to reach the sensor. This disruption triggers the alarm to sound.

  - Photoelectric alarms are more effective in detecting smoldering fires, which tend to produce more significant amounts of smoke before flames become visible.

In addition to these primary types, there are combination or dual-sensor smoke alarms available on the market. These alarms incorporate both ionization and photoelectric technologies into a single unit. Dual-sensor alarms aim to provide broader coverage by detecting both fast-burning and smoldering fires, offering a higher level of protection against different types of fire hazards.

It's essential to note that both ionization and photoelectric smoke alarms have their strengths and weaknesses. While ionization alarms are better at detecting fast-flaming fires, photoelectric alarms are more effective with slow-smoldering fires. To maximize fire detection capabilities, some experts recommend using both types of alarms or combination alarms in homes and buildings to provide comprehensive coverage against various types of fires.