Testboy TV 322 Operating Instructions Manual page 16

Indicator
1. Low battery symbol
2. Data hold
3. Laser sign
4. °C / °F symbol
5. Current temperature value
How it works
Infrared thermometers measure the surface temperature of an object.
The unit's optics sense emitted, reflected, and transmitted energy,
which is collected and focused onto a detector. The unit's electronics
converts the information into a temperature reading, which is display on
the unit. In unit that comes with a laser pointer, the laser serves only for
aiming purposes.
Field of view
Make sure that the target is larger than the unit's spot size. The smaller
the target, the closer you should aim to the target. When accuracy is
critical, make sure the target is at least twice as larger as the spot size.
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