Photo-electric beam sensors typically use which type of light source?
A.
IR
B.
Incandescent
C.
Laser
D.
UV
Photo-electric beam sensors typically use which type of light source?
Photo-electric beam sensors typically use which type of light source?
Photo-electric beam sensors typically use which type of light source?
Photo-electric beam sensors typically use which type of light source?
A.
IR
B.
Incandescent
C.
Laser
D.
UV