Automated low energy photon absorption equipment for measuring internal moisture and density distributions of wood samples

Automated equipment for measuring the moisture and density distributions of wood samples was developed. Using a narrow beam of gamma rays, the equipment scans the wood samples, which are placed on the moving belt. The moisture measurement is based on the ²⁴¹Am photon absorption technique (59.5 keV), where the difference of the linear absorption coefficients of the moist and dry wood is measured. The method requires no knowledge of the thickness of the specimen. The density estimation method is based on the measurement of the linear attenuation coefficient of wood. Comprehensive software including image processing was developed for treatment of the numerical values of the measurements. (author)