1.4.2
Identification of Fire and
Hotspots
The camera will represent zones of
very high temperature as white zones
within the picture. Very small fires or
smouldering material will cause the
automatic iris to close down slightly
but the image of surrounding objects
will remain clearly visible.
1.4.3
Hidden Fires
It is possible that fires may be burning
or smouldering behind doors, in
ducting or indeed in wall or floor
cavities. In such circumstances the
operator should look for areas which
appear whiter when compared to the
surroundings. For example, a fire
behind a door will cause the door to
appear more white against the
background. Similarly, a white area on
an otherwise dark wall could indicate
the area of fire behind the masonry.
1.4.4
Search for Persons and Objects
The camera is not restricted to locating
fires. In many cases the firefighter will
be using the camera in a search for
casualties, to seek out dangerous
items such as fuel tanks or gas
cylinders and also as an aid to
navigation through unknown
premises.
1.4.5
Image Clarity
The sharpness and clarity of the image
provided is related to the temperature
of the scene and objects in view. A
cold room provides little infra red
energy and less detail is detected than
in a warm environment where objects
give off significant energy. In general
the warmer the scene, the more
thermal contrast and hence greater
detail in the picture.
1.4.6
Heat Layers in Closed Spaces
In a major fire, a layer of hot gases
may build up in the upper region of
the closed space. Attempting to use
the camera in this hot layer will cause
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