e2v technologies (uk) limited 2013
CR 113590
P7250UM version 4, page 11
1.5
Operating Notes
The following information relates to a “white-hot” image.
•
Interpreting The Image
o
Relative Temperatures
The image displayed is simply a black and white picture of the infrared
energy entering the lens. The camera displays relative temperature
differences between individual objects and their surroundings irrespective of
overall ambient temperature.
o
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
infrared 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 the greater detail in the picture.
o
Temperature Differences
The camera is set up to display objects at various shades between black for
cooler items and white for hotter bodies, e.g. in a room at 20
°
C a cold drink
would appear black whilst a hot radiator would appear white. However, in a
room at 250
°
C, it is possible that the same hot radiator may appear darker
than, for example, burning materials.
•
Search for Persons and Objects
The camera is not restricted to locating fugitives. In many cases, the user will be
using the camera to search for hidden suspects, guard dogs, dangerous
obstacles, evidence, and drug interdiction operations.
•
Search and Rescue
The camera can view large areas of land and water, searching rapidly.
Searches can be preformed during darkness or full sunlight and in a variety of
weather conditions.
•
Covert Surveillance
Thermal imagers can immediately highlight if a vehicle has recently been moved
(hot tyres, brakes, engine compartment) and is advantageous in urban areas.
The camera can also investigate between homes, buildings and see into dark
garages and entranceways.
•
Windows and Polished Surfaces
Glass is not transparent to long wavelength infrared energy and it is not possible
for the operator to use the camera to look through a window. A white window
would indicate that the window itself is relatively warm. Just as we see
reflections in glass under normal circumstances, it is possible that the camera
can detect infrared reflections in glass, mirrors and polished or painted surfaces.
Care must be taken to ensure that the image seen is not simply a reflection.
Experience will give the operator added confidence.
Summary of Contents for argus
Page 24: ...Argus F Type User s Manual...
