Security System Detection Devices Security System Detection Devices. A security system, even the best, is not a substitute for good basic physical security and procedures. Good doors, deadbolt locks, outdoor lighting, and sensible shrub and tree placement are always your first line of defense. Many local Police Departments will conduct a free security survey of your home, so give them a call. They may be able to give you some good and inexpensive ideas to enhance your overall security.
Contacts are the most common devices used in burglary systems.
Their purpose is to trigger an alarm whenever a door or window is opened. Since recessing contacts requires more labor, the installation charge for recessed contacts is higher than for surface mount. The standard contacts are available, depending on the manufacturer, in a small range of sizes and colors such as brown, white, ivory, or gray. A normally closed system will trigger an alarm if a detection device trips or a wire breaks. The exception to this are Fire Alarms.