Motion Detectors

Passive Infrared motion detector has highly sensitive pyro-sensor operating as the heart of its system. It detects heat radiated from the human body. Segmented lenses divide the whole detection area into passive and active zones. When any warm object like human body moves between the zones, it is detected as a change in voltage by the pyro-sensor. When it detects such movement, it triggers the switching mechanism to operate the connected load.

Practically, the passive infrared motion detector detects movements at right angles (tangential movement) more precisely. With radial movements, reach is usually shortened because detecting a change in temperature in this walking direction is more difficult. While deciding the place for installing the motion detector, this technical parameter must be taken into account. It should be installed in such a way that it is not disturbed or distracted by obstacles or moving objects like fan, curtains, ventilator drafts, etc.

As the pyro-sensor operates by detecting change in the temperature, the ambient temperature plays important role in working of this motion detector. Maximum detection reach distance mentioned for all the PIR motion detectors is measured at the ambient temperature of 25° C. Detection reach distance might change with the change in ambient temperature.
 

High Frequency (HF) motion detector has a cutting-edge HF-sensor operating as the heart of its system. It is a trans-receiver of high frequency microwave signals. First it emits the signals which are reflected back from the surrounding objects, like wall, furniture or floor. It receives the echo of the reflected signals. Whenever there is any change in the received echo that means the movement is detected inside the detection area and the sensor triggers the switching mechanism. This whole process happens at a lightning speed and hence it provides instant response to the movement and turns 'ON' the load immediately. This detection technique is irrespective of ambient temperature and hence it gives the seamless performance over the various climate conditions.

Practically, working of the high-frequency motion detector is irrelevant to the direction of movement. Hence it provides uninterrupted, reliable coverage over the large detection area. High frequency motion detector is highly sensitive and extremely precise in the way it responds. Near the edge of its detection area, it provides better detection to the tangential movements.

Because of its HF-sensor technology, it can detect motion through doors, glass partitions, thin walls, wooden or stud walls, etc. Hence it can be installed under the false ceiling or inside furniture paneling, giving no hint of its presence from outside.