NIR-Monitoring of In-Service Wood Structures

Near infrared spectroscopy (NIRS) was used to study a set of Southern Yellow Pine boards exposed to natural weathering for different periods of exposure time. This non-destructive spectroscopic technique is a very powerful tool to predict the weathering of wood when used in combination with multivariate analysis (Principal Component Analysis, PCA, and Projection to Latent Structures, PLS). Absorbance spectra contained information about weathering behavior, and PLS models to predict exposure time were very strong, with the correlation coefficients above 0.9. These results, and the "non-destructive" nature of this technique, suggest the potential of NIR for monitoring the condition of in-service wood structures.