A method for identifying geometric errors in a machine tool includes the steps of: positioning a reference sphere so as to align its center with a centerline of a tool spindle; attaching a position measuring device having a gauge head to a rotation unit so as to direct the gauge head toward a rotation centerline of the rotation unit; acquiring displacement data relative to the center of the reference sphere by measuring positions of the reference sphere with the gauge head while rotating a rotation target (the swivel unit or the rotation unit) with the gauge head directed toward the center of the reference sphere, the displacement data being dependent on rotation angles of the rotation target; and identifying the geometric errors by least squares method using a mathematical expression having terms containing the geometric errors and representing displacement dependent on the rotation angles, and the displacement data.

A method for controlling, on a metallic coated coil being wound, the coating thickness homogeneity, the method including the following steps of A) measuring a first distance between a first reference point and a first point on the coil surface; B) measuring a second distance between a second reference point and a second point on the coil surface the first and second points on the coil being situated at different spots along the coil width; C) computing a difference between the first distance and the second distance, the difference is noted 12true; D) saving the difference 12true defining a threshold value, comparing each saved difference 12true to said threshold value and/or comparing a sum of differences 12true to the threshold value, emitting an alert when the difference 12true and/or the sum of differences 12true is higher than the threshold value.