An actometer is used to measure your movements, both during the time you are awake and during sleep.
An actometer looks like a watch. You wear the actometer on agreed upon consecutive times – sometimes multiple days or weeks. During this time you also keep a sleep/wake calendar so that we can compare your movements to the times you sleep.
Preceding the examination, you will receive detailed information and instruction on the course of the examination and the practical matters you must take into account.