Apart
from remote controls, one of the most common modern uses for
IR is in the field of security.
"Passive Infra-Red"
(PIR) detectors are used in burglar alarm
systems, and to control the security lighting that
many people have fitted outside their houses.
These detect
the Infra-Red emitted by people and animals.
You've
probably seen TV programmes in which police
helicopters track criminals at night, using "thermal
imaging" cameras which can see in the
dark.
These cameras use Infra-Red waves instead of "ordinary"
light, which is why people look bright in these pictures.
Similar cameras are also used by fire crews and other rescue
workers, to find people trapped in rubble.
Weather
forecasters use satellite pictures to see what's
heading our way. Some of the images they use are taken using
IR cameras, because they show cloud and rain patterns more
clearly. |