Calibration Procedure For A Direct Scanning Densitometer Using Gamma Radiation
Keywords:Gamma radiation, attenuation coefficients, growth-ring characteristics, densitometer calibration
AbstractDirect scanning systems must be properly calibrated so that results may be repeated and verified. A calibration procedure was developed in which blocks of various wood species and densities were scanned with a direct-scanning wood densitomelcr using gamma radiation from a low (Fe55) and a high (Am241) energy source. Wood mass attenuation coefficients for Fe55 and Am241 were, respectively, 18.22 and 0.191 cm2/g at 8% equilibrium moisture content and 17.72 and 0.185 cm2/g under ovendry conditions. These results compare closely (<4%) with those reported in the literature: and as variations in wood characteristics are further quantified, the accuracy of this direct scanning system should improve.
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