Assessment of the error of fiber orientation measurement obtained by laser scanning on several European hardwood and softwood species

Abstract

Scanner measurements allow knot detection and machine strength grading on sawn timber. In particular, laser scanners measure fiber orientation by means of the so-called tracheid effect explained by the fact that the wood fibers conduct concentrated light better in the direction of fibers than across. The LaBoMaP has developed a fiber orientation scanner effective on softwood and hardwood species. In the present work, the fiber orientation measurement error is assessed on several European hardwood and softwood species. A method to measure the intensity of the tracheid effect according to the species and wood cutting plane (radial-longitudinal or tangential-longitudinal) is also proposed, and several underlying artefacts of the tracheid effect are discussed. Results showed that fiber orientation measurement was possible on hardwood species with the LaBoMaP laser scanner, especially on oak.