The relationship between near infrared spectra of radial wood surfaces and wood mechanical properties

Near Infrared (NIR) spectra taken from solid European larch wood samples subjected to axial bending and compression tests revealed an excellent ability to model the variability of mechanical properties using NIR spectroscopy. By including compression wood specimens, whose strength and elasticity is overestimated when modelled by density, in the investigated sample it could be demonstrated that the model is not just based on the measurement of density, but on density, surface geometry and possibly lignin content and composition. It is concluded that NIR spectroscopy shows considerable potential to become a tool for the non-destructive evaluation of small clear wood specimens, e.g. increment cores.