Versatile and highly sensitive, Contrinex photoelectric sensors deliver long-distance, non-contact detection of metallic and non-metallic targets, accommodating variable target color and surface finish. High-frequency switching circuitry senses small, fast-moving objects, even against non-contrasting backgrounds. Photoelectric sensors direct light beams – emitted by a laser diode or LED – toward a distant target. Different operating principles detect either light reflected from the target (energetic-diffuse and background-suppression sensors) or the interruption of the beam by the target (reflex and through-beam sensors). Through-beam sensors utilize a separate receiver, allowing longer sensing distances. Other variants contain a transmitter and a receiver in a single housing. Conveying the light beam into confined spaces using optical fibers eliminates any electrical hazard at the sensing point, ideal for flammable atmospheres.