Microwave Alarm Detectors For Your Home Security Alarm System


These sensors are like others that relay signals to alarm control panels when they detect motion or movement. Microwave motion sensors emit microwave energy to detect movement and emit microwave energy that completely fills its area of detection, much like ultrasonic sensors.
The special properties of microwave energy penetrate most types of surfaces, except metal. Therefore, the sensor may detect motion where detection is not desirable and not detect motion where it is desirable thus a “dead” zone can be created, providing a hole in the security. As the beam can penetrate walls, the sensor will detect motion behind walls, even if such motion is normal.
As the sensors are extremely sensitive to motion, they are also prone to other false alarms. Objects blowing in wind may trigger alarms, even fluorescent lighting, which emits detectable light particles, may trigger a false alarm.
One example of where they are used is to control the automatic doors. We have all been in those large stores where the doors open automatically – so how do these work? There is an electronic sensor system above the door which also controls the motor for the door and its job is to send microwave energy to the immediate vicinity in such a way so that it bounces back. When someone moves into the field of microwave energy, the reflected energy is disturbed thus changing the time it takes to bounce back. The electronics detects this and thus opens the door.