Motion sensors are used in ghost investigations to monitor activity or to alert the investigation crew to potential activity in a remote location. If investigating a household or trying to monitor a lot of different spaces within the same location at once, motion sensors can certainly be of help.
Basic motion sensors work on invisible beams of light. When the beam is broken by an object crossing the path, this trigger the alarm or whatever other alert feature is programmed into the device. Although standard motion sensors are sometimes used on ghost investigations, ones which use infrared technology would be preferable. Infrared motion sensors, unlike standard beam sensors, will view the entire area within its visible scope. If an object that emits a noteworthy heat signature which is measured using the infrared, then this will trigger the alarm. Most infrared motion sensors are programmed to ignore small objects so things like small dogs, raccoons, and other animals will not trigger a false alarm.
Some of the latest infrared motion sensor technology has a built in camera to take photographs whenever the sensor gets triggered. This equipment is ideal for remotely capturing visual evidence of any and all activity that sets off the infrared sensors. Although a little pricey, these devices can provide some of the most reliable infrared evidence around, and you don't even have to be there when it happens!
Ghost Hunting Store - Motion Sensors
Both standard as well as infrared motion sensors, including an infrared motion sensor with a built in camera to snap photos when the sensor is triggered are available at TheGhostHunterStore.com.