Summary
Wood density measurement is related to several factors that influence wood quality. In this paper,
a CT image calibration procedure which allows image quantification in terms of dry bulk density is
presented for three different X- and gamma-ray energies (28.3, and 59.5, and 662.0 keV). The mass
attenuation coefficients measured for a set of eight wood species did not vary significantly, allowing
a single calibration for determination of bulk density of air-dried wood samples at each energy.
The equation for bulk density calibration obtained was validated using a second set of twelve
wood species. Comparison of bulk density determined by CT images, using the calibration procedure
proposed, with values obtained by gravimetric methods, presented a very good linear correlation
coefficient (R2=0.94). The main advantage of CT imaging over conventional techniques for
wood bulk density determination is that it allows detection and quantification of heterogeneities
and internal defects. At the sub-millimetric spatial resolution level, it is possible to identify morphological
and structural aspects of wood samples.
Bulk Density Measurement by a New Tapping System
