Method and apparatus for measuring the rotation of a log and for correcting the rotation error

The object of the invention is a method and an apparatus for measuring the rotation of a log and for correcting the rotation error. The desired sawing position and the necessary rotation angle (A), i.e. how much the log (2) must be rotated from its starting position for it to be in this desired sawing position, is determined for a log (2) by means of a measuring apparatus (3) and a computing unit (3a). After this it is endeavored to rotate the log (2) by the extent of the determined necessary rotation angle (A) to the desired sawing position by means of the rotating apparatus (8). The implemented rotation angle (B) of the log (2) rotated with the rotating apparatus (8) is measured by means of the monitoring device (6) and the marking (10) made on the side of the log (2) before rotation, and if the implemented rotation angle (B) differs essentially from the necessary rotation angle (A) determined earlier, a correction value is determined and the log (2) is rotated again according to this correction value.