[Near infrared spectroscopy of wood sections and rapid density prediction]

In the present report, the use of calibrated near infrared (NIR) spectroscopy for rapid prediction of solid wood density is described. NIR spectra were obtained from the three sections (cross, radial and tangential section) of each Chinese fir sample. The authors found that the spectra of the three sections are different and the correlation coefficients between the laboratory-determined density and the NIR-fitted data are different, too. The prediction results showed that the model based on NIR spectra taken from the cross section is the best, and the correlation coefficients are 0.94 (cross), 0.85 (radial) and 0.81 (tangential), respectively. Using the cross model to predict the density of unknown wood samples, we can see: r2 is 0.977 and the standard deviation (STDEV) is only 0.006.