History of fire alarm.

For the first time, having tamed the fire and learned how to get it, a person faced the problem of preventing and quickly eliminating a fire. After many failures, the society came to the conclusion that special dedicated forces, firemen, who will fight the destructive elements, are needed. But then the next difficulty arose. Firefighters must notify someone! So there was a fire tower. The tallest building in the village, equipped with a first warning system, with a bell, stood in the service of fire protection. For many years, the fire tower successfully performed the function of fire alarm, while the development of cities and the growth of buildings did not limit its functionality. With the loss of the survey and the increase in the area of settlements, the fire tower has become practically useless. Then, to help firefighters, came modern, for that time, technology. In 1837, Semel Morse invented a telegraph machine, which became the first mechanical means of alerting a fire. Unfortunately, the "ancient annunciator" had too many flaws. Price, size, special signal. Therefore, after fifteen years, a new detector replaced the Morsean. A prototype of modern devices, based on the interruption of the loop circuit. In the event of a fire, the hilt turned on the "detector" and a signal was sent to the fire center. Each mechanism was assigned a number, namely, by the number of turns of the handle, that is, the breaking of the chain, it was possible to determine exactly where the ignition occurred. It was these devices that received the famous red coloring. The red gears were placed on the street a short distance from each other. At night, they turned on bright illumination. The devices were improved, new services were added to them. Recording of the time and date, the number of the mechanism, the transmission of the signal to the fire department, etc. Devices repeatedly tried to automate. For example, a bundle was suspended on a plait. At occurrence of fire, the burnout burned out, the cargo fell, getting on the device of inclusion of alarm. Also, fire alarm systems based on changes in spring tension, fluid quantity, and temperature were used. The first sensors appeared, signaling the occurrence of a fire. By the end of the XIX century, fire alarm devices were widely used in Europe, America and Russia. Domestic scientists for the first time developed a combined detector that works, both when the air temperature changes and when the critical temperature level is exceeded. The operation of the device was based on a break in the electrical circuit. So the era of automatic fire alarm began ! With the development of electrical engineering, the number of automatic fire detectors increased. They became more sophisticated, false positives were reduced, critical temperatures were set. Now the sensor could be adjusted to the conditions of the room, because the critical temperatures for the living quarters and the production hall are completely different. Accordingly, the detectors themselves must have different characteristics. So there were categories that divided the fire sensors into four types:

1. Smoke Detectors
2. Gas detectors
3. Heat detectors
4. Flame detectors

The division is still used and is successfully used in modern fire safety systems.

Of course, over time, fire sensors have changed. Become compact, reliable and practical. The modern world can not be imagined without automatic fire alarm. It saves lives, prevents fires, protects our property. The automatic fire alarm system surrounds us here, we are just so used to its existence that we will not pay attention to it.