Hard Fire specializes in fire alarm systems in Ohio, so we thought we would take the time to discuss the two most common types of fire alarms available today: ionization fire alarms and photoelectric fire alarms. Both of them have their uses and advantages, and most fire alarm systems will use both in order to ensure the best fire protection possible.
Ionization Fire Alarms
These types of fire alarms are usually more responsive to flaming fires. They have a small amount of a radioactive material (called Americium-241) that is in between two electrically charged plates. These plates are called electrodes and they are connected to a battery. These electrodes ionize the air and cause electric currents to flow between the two plates. If smoke enters that chamber, it will disrupt that flow of ions and that will trigger the fire alarm.
Photoelectric Fire Alarms
Sometimes when a fire breaks out, it does not instantly burst into flames. Fires can smolder for quite some time before spreading. Photoelectric fire alarms respond to these types of fires by aiming an LED light in a straight line into a sensing chamber. If smoke gets into the chamber, the particles of the smoke will interrupt that light beam and scatter it into different directions. Some of that LED light will go toward the light sensor and trigger the alarm to go off.
If the batteries in the alarm are low, the alarm will start to chirp. But that chirping noise is different from the sound the fire alarm makes when it detects a fire, so people know it is going off because of low batteries and not because there is a fire.
Both types of alarms should be used in most fire alarm systems to ensure there is adequate coverage since fires can break out either instantly or smolder for a while. There are also alarms on the market that combine both of these technologies.
The main purpose of fire alarms is to alert the building’s occupants that there is a fire and they need to evacuate as soon as possible. Using both types of these alarms ensures that, no matter how the fire has started or how quickly it is spreading, there will be an alarm that detects it and sounds a warning.
If you would like more information on fire alarm systems in Ohio, call Hard Fire at 1-800-848-1301 or 614-882-2990 or you can Contact Us.