There are two potentiometers in the module to control the sensitivity of the sensor. The detection distance can be increased or decreased using a potentiometer while the delay time can be increased or decreased using the other potentiometer.
This module has two working modes. Repeatable mode(H) and Non-Repeatable mode(L). In Repeatable mode, the Dout will supply a high signal for a particular time once it detects a motion in its range and then goes low. But in Non-Repeatable mode Dout goes high once it detects any motion and remains high for the time the object of which motion was detected remains in the range of the sensor. This module is usually used for automatic lights, security systems and in many other machines for automation. This PIR sensor is often referred to as “PIR”, “Pyroelectric”, “Passive Infrared” and “IR Motion” sensor.