As I approach my 40th year in the electronic security business, sometimes I reflect on things I was involved with that didn’t work out so well. I must confess to my faithful readers that I am likely indirectly responsible for thousands of false burglar alarm signals that occurred in the Atlanta area during the early 1980s.
At the time, the alarm equipment distribution outlets I was working for sold thousands of microwave-only motion detectors. The problem was that if the device was aimed so that the microwaves would penetrate the “back wall” of the protected area, the “elephant” effect caused false alarms. As the microwaves passed through the wall, they could reflect off a large moving object (such as a truck) outside the building and interpret the reflection as the human-sized “target” it was designed to detect.