Door alarms prevent intruders from breaking into a house by emitting loud sounds to alert homeowners. They use a number of detection systems, such as infrared and electric current, to detect suspicious motions or the presence of a person outside an entrance. Some door alarms have an emergency call feature that automatically calls local law enforcement when an intrusion attempt is detected. When used in business establishments, they may include special sensors that set off the alarm when unpaid merchandise is passed through the door. Door alarms may also be installed over other entryways, such as windows.
Do you have a product you want to write about? Please CONTRIBUTE. If it passes our editorial standards, we will add it in and put your name and/or link your website as a contributor.
