FLIR GF7 Series, Руководство пользователя

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Measuring temperatures 11
11.1 General
To measure a temperature, you can use one or more measurement tools, e.g., a spot-
meter or a box. For more information, see section 18
Working with measurement tools ,
page 58.
By using color alarms (isotherms), temperature anomalies can easily be discovered in
an infrared image. For more information, see section 19
Working with color alarms and
isotherms , page 67.
Note The temperature measurement functionality is enabled by a setting. Select
( Settings ) > Application options > Gas camera mode > Temperature measurements .
11.2 Achieving a good image
A good image depends on several different functions and settings, although some func-
tions and settings affect the image more than others.
These are the functions and settings that you need to experiment with:
• Adjusting the infrared camera focus.
• Adjusting the temperature scale.
• Selecting a suitable color palette.
• Changing the measurement parameters.
• Performing a non-uniformity correction (NUC).
• In some situations, you may also want to hide the camera overlay for a better view.
11.2.1 To keep in mind
• A thermal camera has a resolution limit. This depends on the size of the detector, the
lens, and the distance to the target. Use the center of the spot tool as a guide to the
minimum possible object size, and get closer if necessary. Make sure to stay away
from dangerous areas and live electrical components.
• Be careful when holding the camera perpendicular to the target. Be observant of re-
flections, especially at low emissivities—you, the camera, or the surroundings may be-
come the main source of reflection.
• Select a zone of high emissivity, e.g., an area with a matte surface, to perform a
measurement.
• Blank objects, i.e., those with low emissivities, may appear warm or cold in the cam-
era, because they mainly reflect the environment.
• Avoid direct sunlight on the details that you are inspecting.
• Various types of faults, e.g., those in a building’s construction, may result in the same
type of thermal pattern.
• Correctly analyzing an infrared image requires professional knowledge about the
application.
11.3 Adjusting the camera focus
It is very important to adjust the focus correctly. Incorrect focus adjustment affects how
the image modes work. It also affects the temperature measurement.
11.3.1 Manual focus
You can adjust the focus manually by rotating the focus ring. For more information, see
section 21.4
Adjusting the infrared camera focus manually , page 81.
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