Ultrasonic Proximity Sensors
Posted in Sensor on Jul 3rd, 2007
Ultrasonic sensors are small devices used to detect the presence of intruders and other foreign objects. These can discreetly be placed in courtyards and inside homes to detect the presence of moving objects alien to the surroundings. They operate at frequencies in the range of twenty-five to forty kilohertz, which is way above the human [...]
