Fig 1. The IRT657's controls, indicators and physical features
A
B
C
D
A. Laser Pointer
B. Infrared Sensor/Lens
C. Measurement Trigger
D. Battery Compartment
E. Backlit Liquid-Crystal
Display
F.
Button (laser on or off)
6
I
E
F
G
H
G.
Button
(backlight on or off)
H. °C/°F Button (temperature
unit selection)
I. Laser Identification/
Certification/Warning/Safety
Labels (on left side); see
below