After having analysed a number of measurement principles, it was decided to develop a radically new, now patented, measurement principle. Rather than utilising colour, or brightness, the new principle relies on the differing light scattering properties of wood and bark. As a laser beam hits wood it is scattered by the fibres and the semi-transparent lignin. It is scattered most efficiently in the direction of the fibres. Knowing the actual bark content in real time, it is possible to minimize excess debarking and unnecessary wood losses.