Applications include position detection for electrical overhead conveyors, precision fill-level measurement, and monitoring of coiling and uncoiling processes in paper, sheet-material, and sheet-metal processing. Measurement is mostly independent of the direction of motion, angle, and the reflection and color of the object to be scanned. Dark objects with diffuse reflection values of <6% can be reliably detected, even in front of bright backgrounds. Measuring ranges and switching distances can be taught in or set directly by entering the respective distance. Features include digital resolution of 1-mm analog output within a range of 0 to 10 V or 4 to 20 mA, and measuring range can be entered manually, by means of teach-in or via RS-232 interface. The sensors are pnp/npn switchable.