Measuring temperatures
General
To measure a temperature, you can use one or more measurement tools, e.g., a spotmeter or a box. For more information, see section Working with measurement tools.
By using color alarms (isotherms), temperature anomalies can easily be discovered in an infrared image. For more information, see section Working with color alarms and isotherms.
The temperature measurement functionality is enabled by a setting.
Select 
(Settings) > Application options > Gas camera mode > Temperature measurements.
Achieving a good image
A good image depends on several different functions and settings, although some functions 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 infrared image (automatically or manually).
Selecting a suitable temperature range.
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.
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 reflections, especially at low emissivities—you, the camera, or the surroundings may become 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 camera, 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.
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.
Manual focus
You can adjust the focus manually by rotating the focus ring. For more information, see section Manual focus.
Autofocus
You can autofocus the infrared camera by pushing the Autofocus button. For more information, see section Autofocus.
When the camera is set to autofocusing with the laser method (Settings > Device settings > Focus > Auto focus >Laser), do not point the camera at the face of a person when you use the autofocus function. The laser beam can cause eye irritation.
Continuous autofocus
The infrared camera can be set up to perform continuous autofocusing. For more information, see section Continuous autofocus.
Do not point the camera at the face of a person when the continuous autofocus function is on. The camera uses laser distance measurements (that are continuous) for the focus adjustments. The laser beam can cause eye irritation.
For large lenses that cover the laser transmitter and receiver, the laser functionality is disabled. This means that continuous autofocus is not available.
Adjusting the temperature scale
By default, the camera continuously adjusts the image for the best image presentation. Use this automatic mode first, but do not hesitate to adjust the temperature scale of the infrared image manually. For more information, see section Infrared image adjustment.
To adjust the temperature scale, do the following:
Touch the soft button
to enter manual image adjustment mode.Do one or more of the following:
To simultaneously change the temperature scale minimum and maximum limits, place your finger on the screen and move it up/down.
To change the minimum or the maximum limit, do the following:
Touch the maximum or minimum temperature that you want to change.
Place your finger on the screen and move it up/down to change the value of the highlighted temperature.
To enhance the details of a certain point of interest in the image, touch that point on the screen. The image will be auto-adjusted based on the thermal content of the area around the touched point.
To prevent further unintentional adjustments, you can lock the touch screen.
To lock the screen, touch the
icon.To unlock the screen, touch the
icon.
Changing the camera temperature range
General
The camera is calibrated for different temperature ranges. Available temperature range options are dependent on the camera model.
For accurate temperature measurements, you must change the Camera temperature range setting to suit the expected temperature of the object you are inspecting.
For more information, see section About calibration.
Procedure
Follow this procedure:
Push the navigation pad to display the menu system.
Select
(Settings) and push the navigation pad. This displays the Settings menu.Select Camera temperature range and push the navigation pad. This displays a dialog box.
Select the appropriate temperature range and push the navigation pad.
You can also assign the function Switch temperature range to one of the programmable buttons. For more information, see section Programmable buttons.
Changing the color palettes
You can change the color palette that the camera uses to display different temperatures. A different palette can make it easier to analyze an image. For more information, see section Color palettes.
To change the color palette, do the following:
Push the navigation pad to display the menu system.
Select
(Color) and push the navigation pad. This displays a submenu.Use the navigation pad to select a different palette.
Push the navigation pad to confirm and exit the menu mode.
Changing the measurement parameters
For accurate measurements, it is important to set the measurement parameters:
Emissivity.
Reflected temperature.
Object distance.
Atmospheric temperature.
Relative humidity.
External IR window compensation.
Emissivity is the most important measurement 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.
You can set the measurement parameters globally. You can also change the Emissivity, Reflected temperature, and Object distance parameters locally for a measurement tool.
For more information, see section Changing the measurement parameters.
Non-uniformity correction (NUC)
General
When the thermal camera displays Calibrating... it is performing what in thermography is called a ”non-uniformity correction” (NUC). An NUC is an image correction carried out by the camera software to compensate for different sensitivities of detector elements and other optical and geometrical disturbances1. For more information, see section About calibration.
An NUC is performed automatically, for example at start-up, when changing a measurement range, or when the environment temperature changes.
You can also perform an NUC manually. This is useful when you have to perform a critical measurement with as little image disturbance as possible. You may, for example, want to perform a manual calibration just before you start recording a video sequence.
Performing an NUC manually
To perform a manual NUC, push and hold down the image archive button
for more than 2 seconds.
You can also assign the function Calibrate to the one of the programmable buttons. For more information, see section Programmable buttons.
Hiding all overlay
The camera overlay consists of overlay graphics and image overlay information. The overlay graphics include items such as measurement tool symbols, result tables, and status icons. The image overlay information, which you activate on the Settings menu, provides additional information such as the date, time, and items related to temperature measurements. For more information, see section Image overlay.
You can hide all camera overlay by touching the soft button 
.
You can also assign the function Hide image overlay graphics to one of the programmable buttons. For more information, see section Programmable buttons.