Electromagnetic Alarms Brattleboro VT
Most intrusion detection systems in use today utilize some form of electrical circuit running through wires, mechanisms, metalized tape or foil. If any part of the electric circuit running through two pieces of metal in the door locks or window lock mechanisms , or if a strip of metallic tape on the window glass is broken, it trips an alarm.
Circuits work well when an intruder attempts entry as one would expect, by opening a door or window. Burglars however, know how to use crowbars and other burglary tools to get through doors without disrupting these electrical circuits. In warm climate regions, houses may have thin walls, and entry can be gained by cutting through a wall. Tape or wire mesh in the wall would have to be torn or cut through to gain entry, thus tripping the security alarms .
Limitations occur in a circuit system because the gap or break can be bridged when the burglar breaks the tape or magnetic connection with a long wire or piece of metalized tape, prying open a door or window frame without setting off the alarm.
Magnetic Contact Circuits
Electromagnetic systems are often used on doors to apartment buildings and secure areas in government offices. They use a magnet in one sealed enclosure and a switch in another sealed enclosure and when the magnetic contact is broken, the alarm signal sounds.
In order to open a door protected with a magnetic door latch, a button has to be pushed by an attendant to allow the door to be opened by the visitor...