![Dojava požara](https://tesla.rs/wp-content/uploads/2020/03/sistem-umrezavanja1-1.jpg)
Automatic fire alarm system at four hydropower plants
May 19, 2020![Tesla sistemi](https://tesla.rs/wp-content/uploads/2019/01/Brod-Greben.jpg)
The BELEXPOCENTAR building has received a new metal detector door that will serve to increase the safety of its guests.
Metal-detector doors are intended for detection and prevention of bringing weapons into objects. When an armed person tries to pass, a visual and audible alarm is activated.
The first metal detectors, the forerunners of today’s modern ones, were made in America in the mid-1960s and were used in sawmills to detect nails in trees. Based on this device, door-shaped detectors are assembled.
The first places where doors were installed were airports.