© PCE Instruments
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4.2 Using the thermal imager
For basic operation, follow these steps:
1. Set the function switch to any position.
2. Press the “IR” button to switch ON the thermal imager. Target the object with the thermal imager
lens.
3. The display will show the temperature measurement in the upper left hand corner for the
targeted area along with the currently selected emissivity value.
4. In thermal imaging mode, the laser pointer and display cross hairs can be used to assist in
targeting. These tools can be switched ON or OFF in the Setting menu.
5. In Thermal imaging mode, the highest temperature will be auto marked by a red cross and the
lowest temperature will be auto marked by a blue cross. This can be switched ON or OFF in the
Setting menu.
6. In Thermal imaging mode, the meter continues to operate normally as a multimeter, allowing
any of the electrical functions to be used.
7. Press the HOLD button to hold the thermal image frame, then press and hold the HOLD button.
You will capture the screen and save a bitmap with measurement data to the SD card. The
saved bitmap can be analysed later by the PC software or smartphone APPs.
8. The thermal imager’s FOV (Field of view) is 21 x 21 degrees.
9. FOV is the largest area that your imager can see at a set distance.
10. The following chart lists the horizontal lFOV, vertical FOV and IFOV for lens:
IFOV (Instantaneous Field of View) is the smallest detail within the FOV that can be detected or
seen at a set distance. The unit is rad. The formula is:
IFOV = ( Pixel Size )/ ( Lens focal length )
D:S
theoretical
( = 1/ IFOV
theoretical
) is the calculated spot size based on the pixel size of the thermal
imager detector array and lens focal length.
Example: If the thermal imager uses a 9 mm lens because the pixel size of the detector is 34µm,
horizontal FOV is 21°, vertical FOV is 21°, the IFOV is 34µm/7.5mm = 4.53mrad;
D:S
theoretical
( = 1/ IFOV
theoretical
) = 220:1
D:S ( = 1/ IFOV ) is the spot size needed to provide an accurate temperature measure. Typically,
D:S
measure
is 2 to 3 times smaller than D:S
theoretical
, which means the temperature measurement
area of the target need to be 2 to 3 times larger than that determined by the calculated theoretical
D:S.
