Motion detection has always been, and will remain, one of the original mainstays of the electronic security industry. These devices really got the industry started and are still the first line of defense in securing the protected premises and the perimeter of a facility.
The 1950s saw the development of the first volumetric (early motion) sensors. Soon after came photoelectric beams and then ultrasonic. Advanced Devices Laboratories (ADL) released the first passive infrared and microwave detectors in the 70s, according to Larry Tracy, president of Aleph America , Reno , Nev.
“Back then, one of the biggest mistakes we probably made in the industry as a whole was not getting patents for products,” he said. “Dual technology devices, microwave and passive infrared sensors (PIRs) were brought to market late in 1981,” he added. In 1986, Tracy, who was with Detection Systems at the time, made the first animal immune sensor, finally addressing the problem of false alarms with optics and other filters.
The addition of motion sensors provided cost-effective coverage of much larger spaces, according to Gary Buth, director of Technical Sales, Takex America Inc., Santa Clara , Calif. “Motion sensors were designed with the intention of offering volumetric coverage of a particular room providing detection of potential intruders if they moved within the protected area,” said Buth. “This added detection capability supplemented the typical perimeter sensors installed on the various openings of a structure. Today, motion sensors are being used both indoors and outdoors to provide early warning detection around the external perimeter of structures,” he added.
