Being the Sport! - IGIT IEEE STUDENT BRANCH

COFFEE MAKER
Technology in environment- was so thrilled to get this topic, because I visualize myself as some kind of
enviro freak. But it gradually dawned on me how tough it is- it is such a wide area I had no idea where to
start, or rather with what to start. After some consultations with professionals as to what is hot in the field
right now, I decided to enlighten you ‘energy crisis-oblivious’ souls with “OCCUPANCY SENSORS”.
The two parent sensor technologies are infra-red (IF) or passive, and ultrasonic/ultrasound (US)
technology.
• The IF technology:
-uses a sensor tuned to detect heat/ infra-red radiations emitted by moving bodies. The lights are turned-
on when these radiations are detected, and turned- off if no radiation is detected for a set period of time
(usually 15 minutes).
Drawback: Motion only in line-of-sight is detected, i.e. it cannot be used for places with bends.
Thus, it is used in open spaces like hallways, conference rooms.
• The US technology:
Sensing You
- makes use of ultrasound generator and receiver. The generator emits sound waves and any motion
causes a change in the reflected frequency detected by the receiver. It can detect motion that is not line-ofsight
also. Thus, it can be used for larger areas, open offices, bathrooms, unusually shaped areas.
Aditi
Occupancy sensors are energy saving devices which achieve the
aforementioned purpose of saving electricity by turning lights on when
there are occupants in the area under consideration, and switching them
off when empty. These have proved quite effective in places like hotels
where the basic mentality of the customers is that since they’re paying
for it, why bother turning off the lights? Or in offices, where the
company is paying the bills-not you. I shall be discussing two parent
and two child technologies for these sensors.
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