A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view, and it provides an out put of 5V.
This sensor that was developed by Bbiri Applied ICT Centre Limited detects an object that emites out infrared and it provieds an out put, It has the potentiometer space on board that can be used in adjusting the senstivity and you can also adjust the on time or the time that it takes when its out put is high 
This module also has  continuous triggering in it .  The out put will continue in one position until the object gets out of it .