Magnetic Sensors are the most easily understood security system “how it works” by ordinary users. Also, their cost is comparatively lower. In addition, they are easy to install and are an important part of DIY systems. For all these reasons, Magnetic Sensors are widely used.
Although magnetic sensors are generally low in cost, it is also possible to find cheaper options among them. Some models offer a password entry panel for the host. The cheaper models, on the other hand, only have an on-off switch. If this button is not accessible, it can do the same with expensive models.
These inexpensive and simple models are mostly used on medicine cabinet doors and windows that are out of reach of children. They emit a high-pitched alarm sound when the lid is opened and are simply silenced with the on-off button.
How do Magnetic Sensors Work?
The working principle of magnetic sensors is actually quite simple. Most intrusion detection systems in use today utilize some form of the electrical circuit running through wires, mechanisms, metalized tape, or foil. If any part of the electric circuit runs 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 Sensors and Contact Circuits
Electromagnetic systems with magnetic sensors are often used on doors to apartment buildings and secure areas in government offices. There is a magnet in one closed section and a switch in another closed section, and if the magnetic contact is broken, the alarm signal sounds.
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. The button merely moves the door mechanism to the open position. When the electrical switch is turned off (the button is released), the mechanism closes again. These systems are used in place of key/lock systems and they ensure a human being is controlling access. Electromagnetic locking systems can withstand a ton of force, making them harder to break.
Security systems based on electrical circuitry will protect the perimeter of a home, but will not be effective if there is someone already inside your home. If you have valuables such as jewelry, art, or collections in your home, you would be wise to consider motion detection systems.
To complement the shortcomings of magnetic sensors, new technological developments are occurring every day. You can find the most up-to-date information on the company links on the page.