Polychromatic X-Ray Attenuation Characteristics and Wood Densitometry Applications

The use of polychromatic X-ray energy in wood densitometry complicates the mathematical relationship between the material and X-ray attenuation. Attenuation of polychromatic X-ray energy through cellulose acetate was investigated and characterized. Under polychromatic radiation with 30 keV maximum photon energy, an attenuation coefficient of 0.638 cm 2 /g was determined for samples of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) from two trees at 9% equilibrium moisture content. X-ray energy was sensitive to wood moisture content within a 2% range.