AEA Amatrol's Sensor Logic Systems Practice Test

Photoelectric sensing works by converting light into an electrical signal in a photodetector. When the emitted light reaches the detector, the light increases charge carriers in the semiconductor, changing its conductivity and producing a current. That change in signal indicates whether the beam is uninterrupted or altered by an object, so the presence of the object is detected through photoconduction. The other terms describe how light interacts with a surface, but they don’t define how the sensor produces a usable electrical signal from light.