Method of measuring the length of winding material running onto a winding beam

A method of measuring the total length of a yarn type material as it is wound onto a wound package, comprising steps of

• contacting the material with a measuring roll which runs synchronously with the material, the measuring roll and the wound package each being connected to a respective rotational displacement measurer for ascertaining the rotational displacement, and
• during continuous winding operation, directly measuring the total length of material running onto the wound package, by sensing measuring roll rotation, and determining the relative circumference (Uw.sub.rel) of the wound package on the basis of the measuring roll's size and storing the relative circumference, while monitoring the measuring roll for slippage, and
• when slippage is detected between the material being wound and the measuring roll, indirectly measuring the total length of material running onto the wound package by increasing the measured value for the total length by the relative circumferential length of the wound package with each rotational step of one unit of angle of the wound package, the last value to have been determined in continuous operation for the relative wound package circumference (Uw.sub.rel) being increased with each rotational step of one unit of angle of the wound package by the relative change in wound package circumference (dUw.sub.rel /d.phi..sub.w),
• wherein the relative wound package circumference (Uw.sub.rel) and the relative change in wound package circumference (dUw.sub.rel /d.phi..sub.w) with rotation of the wound package during continuous operation are ascertained and stored, and these stored values are used during slippage operation in order to determine the actual length (l.sub.s) of the material wound during slippage operation.