Fluke Ti20 - Manual (Page 15)

Getting Started
Operating the Controls
1
1-7
Table 1-3. Features and Controls
Number Description
A Focus control
B Optical channel
C Laser aperture
D Wrist strap and attachment clip
E Trigger. The trigger is used to freeze a thermal image. Press the trigger one time to freeze
the image for evaluation. You can save the image or press and release the trigger again to
delete the image.
F USB port
G AC adapter terminal
H Display
I The three soft keys (
F
,
G
, and
H
) are used to navigate the menu structure of the
Imager, access all functions, and select values for the various adjustable parameters. The
G
soft key is also used to turn the Imager On and Off. Press and hold
G
for two
seconds to turn off the Imager.
J Battery compartment
K Threaded tripod mount
Operating the Controls
The following sections describe the purpose and function of the two Imager controls,
focus and trigger.
Focusing the Imager
Proper focus is critically important in radiometric imaging applications. The correct focus
ensures that the infrared energy is being properly directed onto the pixels of the detector.
Without the correct focus, the thermal image appears blurry and the radiometric data will
be inaccurate. Correct focus is necessary to accurately capture a thermal image.
Focus the Imager by turning the focus control in a clockwise or counterclockwise
direction (similar to the operation of a single lens reflex 35 mm photographic camera).
The Imager is designed to focus at a minimum distance of 61 cm (24 in) or less (rotated
fully clockwise as viewed from the rear of the instrument) and to a maximum of infinity
(rotated fully counterclockwise).
As you turn the focus control, you will see a changing, live, thermal image on the display.
When your target comes into focus, it will appear sharper. When the target moves out of
focus, it becomes blurry. One way to verify proper focus is to find what focus adjustment
produces the highest temperature indication on the display (keeping emissivity and
Reflected Temperature Compensation (RTC) values constant, preferably with emissivity
set at 1.0 and RTC disabled). See Figure 1-4 for an illustration of focusing the Imager.