Rolled sheets in the metal industry are wound on coils for transport. It is important that directly before and also after the coiling, to check the position and the edge condition of the metal strip. optoCONTROL optical micrometers are used for this. If the edge of the coil is within the measuring range during the winding or unwinding, the position and the edge structure can be determined from this. This technique ensures that the coil is wound correctly and also that the correct metal strip quality has been delivered for the unwinding.