Recommended Values; Procedure - FLIR T4 series User Manual

16 Working with measurement tools
• Atmospheric temperature, i.e., the temperature of the air between the camera and the
object of interest.
• Relative humidity, i.e., the relative humidity of the air between the camera and the ob-
ject of interest.
• Reflected temperature, which is used when compensating for the radiation from the
surroundings reflected by the object into the camera. This property of the object is
called "reflectivity".
• Emissivity, i.e., how much radiation an object emits, compared with the radiation of a
theoretical reference object at the same temperature (called a "blackbody"). The op-
posite of emissivity is reflectivity. The emissivity determines how much of the radiation
originates from the object as opposed to being reflected by it.
Note There is an Emissivity mode setting, which you can use to enter the emissivity
by material instead of by value. Select
era > Emissivity mode > Select from materials table.
Of the object parameters, Emissivity is the most important parameter to set correctly. If
the Emissivity is set to a low value, the Reflected temperature also becomes important.
The parameters Object distance, Atmospheric temperature, and Relative humidity are
relevant for longer distances. The External IR window compensation must be activated if
a protective window or external lens is used.

16.5.3 Recommended values

If you are unsure about the values, the following are recommended:
Object distance
Atmospheric temperature
Relative humidity
Reflected temperature
Emissivity

16.5.4 Procedure

You can set the object parameters globally. You can also change the Emissivity, Re-
flected temperature, and Object distance parameters locally for a measurement tool.
Local parameters are normally only effective for a fixed setup, where each measurement
tool is set to a specific object of interest. In a general handheld application, the global pa-
rameters are usually sufficient.
Note Of the object parameters, Emissivity and Reflected temperature are the two most
important to set correctly in the camera.
16.5.4.1 Setting global parameters
Follow this procedure:
1. Push the joystick to display the menu system.
2. Use the joystick to go to
#T559879; r. AP/36066/36066; en-US
(Settings) > Device settings > Set up cam-
1.0 m (3.3')
20°C (69°F)
50%
20°C (69°F)
0.95
(Measurement parameters).
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