Photoelectric Sensors are optical detection devices that use a modulated light transmitter—typically infrared or red LED—and a photoelectric receiver to detect the presence, distance, or alignment of objects along an optical path. Available in thru-beam configurations (where transmitter and receiver are housed separately), retro-reflective configurations (using a corner-cube reflector), and diffuse-reflective modes, these sensors excel at long-range object detection and high-speed counting. Key hardware features typically include precision glass or PMMA optical lenses, potentiometer or light-on/dark-on selector switches, visible alignment LEDs, compact rectangular or cylindrical resin bodies, and washdown-rated enclosures.