FLIR GFx320, User Manual

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Working with measurement tools 20
Follow this procedure to create and set up a difference calculation:
1. Turn the mode wheel to or .
2. Push the button to display a menu.
3. Move the joystick left/right to go to the Edit tab.
4. Move the joystick up/down to select Add difference .
5. Push the joystick to display a dialog box.
6. Do the following and push the joystick to confirm each choice:
6.1. To select the first function in the difference calculation, select Function 1 and
push the joystick. Move the joystick up/down to select the measurement tool
you want to use for this function.
6.2. (Not applicable if there is only one measurement tool.) To select the ID of the
measurement tool, select
Id and push the joystick. Move the joystick up/down
to select the ID.
6.3. (Not applicable to spotmeter and reference temperature.) To select the result
type of the measurement tool (
Min. , Max. , Avg. ), select Type and push the joy-
stick. Move the joystick up/down to select the result type of the measurement
tool.
7. Do the following and push the joystick to confirm each choice:
7.1. To select the second function in the difference calculation, select Function 2
and push the joystick. Move the joystick up/down to select the measurement
tool you want to use for this function.
7.2. (Not applicable if there is only one measurement tool.) To select the ID of the
measurement tool, select
Id and push the joystick. Move the joystick up/down
to select the ID.
7.3. (Not applicable to spotmeter.) To select the result type of the measurement
tool (
Min. , Max. , Avg. ), select Type and push the joystick. Move the joystick
up/down to select the result type of the measurement tool.
8. Push the button to confirm and leave the setup mode.
20.4 Changing object parameters
20.4.1 General
For accurate measurements, you must set the object parameters. You can do this locally
or globally. This procedure describes how to change the object parameters globally.
20.4.2 Types of parameters
The camera can use these object parameters:
• Emissivity , i.e., how much radiation an object emits, compared to the radiation of a
theoretical reference object of 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.
• Reflected apparent temperature , which is used when compensating for the radiation
from the surroundings reflected by the object into the camera. This property of the ob-
ject is called reflectivity.
• Object distance , i.e., the distance between the camera and the object of interest.
• 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.
• External optics temperature , i.e., the temperature of any protective windows etc. that
are set up between the camera and the object of interest. If no protective window or
protective shield is used, this value is irrelevant.
#T810169; r. AN/42241/42268; en-US 64