Why can the alarm system sound when there is no fire?

Fires happen, fire alarms are one of the most important factors to inform all residents living in the area. But how does it work?

Fire engines are dispatched to the fire alarm school.

Structure of a fire alarm system

Automatic fire alarm system is a system consisting of a set of devices that are responsible for detecting and alarming when a fire occurs.

The detection of fire signals can be done automatically by devices or by humans and operates continuously for 24/24 hours.

Fire fighting tools.

A basic automatic fire alarm system will be composed of 3 main parts: fire alarm center, input device, output device. In particular, the fire alarm center is designed as a cabinet, including the main equipment: a main control panel, modules, a transformer, a battery.

Input devices include smoke detectors, heat detectors, gas alarms, fire alarms . and emergency switches. Output devices include auxiliary display boards, alarms, alarm lights, emergency exit lights, automatic telephone dialers.

All these devices will be operated according to a simple but effective mechanism, ensuring high accuracy.

Operation principle of fire alarm system

Operation process of fire alarm system is a closed process : Input device receives signal - transmits signal to fire alarm center - output device sends an alarm signal.

Operation principle of fire alarm system.

When there is a fire signal such as a sudden rise in temperature, the appearance of smoke or sparks - input devices such as detectors, emergency switches will receive signals and transmit information of the incident. about the fire alarm center.

Here the center will process the information received, determine the location where the fire occurred and transmit the information to the output devices (auxiliary display panel, bell, whistle, lights). At this time, these devices will broadcast sound and light so that people can identify the area where the fire is occurring and handle it promptly.

Why is the fire alarm system prone to "fool"?

Sophisticated operation is but the fire alarm system seems to be easily "fooled" , as in the recent case of false fire in Xa La, or many similar incidents happened in the past.

Of course, everything has a cause and it comes from the input devices of the fire alarm system.

As mentioned above, the input system includes a heat detector. However, the heat transfer rate in the air is very slow, so until the heat detector receives the signal, it is likely that the fire is out of control.

Therefore, in order to increase the ability to recognize the fire early, people add smoke detectors, working very acutely. Smoke transmitted in the air with a speed of up to 122m / minute can soon transmit signals to the fire alarm center.

Smoke alarms often work very responsibly.

But because of that, there are many cases where the fire alarm system has been very . pathetic just because someone smokes. Or if someone accidentally caused a small fire with smoke and heat (like burning votive gold), the fire alarm system would immediately be activated.

Manual emergency alarm button.

In addition, the input system also has an emergency alarm device by hand, so that when the system fails, people can still start the fire alarm manually.

However, some individuals can take advantage of this to create false alarms to benefit themselves, or simply they want . naughty.