Application of high-frequency densitometry to detect changes in early- and latewood density of oak (Quercus robur L.) due to thermal modification

The aim of the present investigation was the identification of changes in the density of oak (Quercus robur L.) due to the influence of thermal modification. The reduction of the density was recorded by High-Frequency Densitometry and compared to measurements based on the gravimetric method. To identify changes in density, the initial density and the density after thermal treatment were determined using the same sample. In conclusion, results from the High-Frequency Densitometry Method show smaller deviations than those from gravimetric method. In addition, High-Frequency Densitometry provides reasonably good results with respect to the localisation of changes in density within an annual ring. As expected, in contrast to the Gravimetric Method the High-Frequency Densitometry Method were proved to be applicable to localise the change of the tree-ring density. It can be summarized that the measurement of the local density change can be realized by High-Frequency Densitometry. The density of earlywood was significantly more reduced due to thermal modification than the density of latewood.