Motion detectors or sensors are a part of most home and business security systems, but they’re also used to automatically open doors, and activate sinks and toilets in restrooms. There are two types of motion detecting systems: active and passive. Active sensors send out ultrasonic sound waves and passive sensors detect infrared energy. There are outdoor motion sensor lights that automatically turn on when motion is detected, and there are infrared motion sensors alarms and cameras, too. A third type of motion sensor is the photo-electric sensor which uses a laser beam to detect when something crosses the light’s path, sounding an alarm. Find proximity sensors and sensor accessories for your home or office at Zoro.