Veneer sheet density measurement by the 55Fe gamma attenuation method

This paper presents a very low gamma energy radiation method for the measurement of density distributions of veneer sheet. The method is based on a narrow beam measurement geometry, where the equipment scans the specimen sheet placed between the 55Fe radiation source emitting 5.9 keV photons and the Nal-detector. The density distribution is determined by measuring the number of photons passing through the veneer sheet. By the method the dry wood density can be determined by measuring also the moisture content of the sheet. The dry wood density can be estimated with good accuracy without moisture measurement when the moisture variation is limited to a few per cent.