Recently, Mountain Alarm was asked to provide expert information to Redfin.com. The following excerpt was provided by our Colorado GM, Jeff Williamson:
What is a contact sensor? How do you determine the right number of contact sensors for your home?
A contact sensor is a device that indicates whether something is open or closed. The most important doors in your home to protect are outside, ground-level doors.
In most cases, a contact sensor is used to monitor a door or window but they can be used for other purposes as well. A sensor usually has two pieces: one piece houses a transmitter to send signals to the security system and two pieces of metal surrounded by a glass tube called a “reed switch,” while the other piece houses a magnet. When the magnet is placed near the transmitter, one metal piece is drawn close to the other one, closing the circuit which indicates a “closed” condition. When the magnet moves away from the switch, the metal pieces move apart, opening the circuit which indicates an “open” condition. You install one piece of the sensor on the door frame and the other on the door itself. When the door is closed, the magnet and switch are near each other and the sensor reports that it is “closed,” but when the door opens, the magnet and switch are separated and the sensor reports that it is “open.” So, when the system is armed, the opening of a window or door will send a signal to the panel, setting of the alarm.
First, do a quick count of all the doors and windows you’d like to protect in your home. Protecting all outside doors is essential for a home security system as most burglars will come through a door instead of a window. The second step is to go beyond the security of your home, and consider anything you want to monitor inside your home such as the jewelry box, or a gun safe. The more sensors you install, the more information you have to keep your home and family safe!
Read the whole article here: