The arrangement contains at least two laser measurement transducers (4,5) connected to an evaluation unit (8). The measurement transducers are arranged at a distance apart. An analogue/digital converter (7) is connected between the transducers and to the evaluation unit. The evaluation unit has a memory for each transducer and a comparator connected to the memories. For three or more transducers, the distances between adjacent transducers are different. The evaluation unit output can be connected to a control loop.
