About Interpretation Methods of Acoustic Tomography Results of Pine Wood

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Abstract

Acoustic tomography is based on measurements of the propagation time of sound impulses. Velocity of sound impulses characterizes the state of the wood. Acoustic tomography is used for wood assessment and to determine the quality of the wood. Because the sound wave propagates more rapid in high density wood. The main objective of this work was to develop interpretation methods of the Arbotom results to estimate the quality of the wood. The object of research is pine, because it is less amenable to fungal diseases than other species of trees and it is a valuable specie. Acoustic tomography was carried with the Arbotom machine at tree height 130 cm above ground. From 6 to 12 sensors was used, depended on the diameter of the tree. Healthy wood quality was evaluated on the average velocity of sound transmission between sensors. In order to reduce the influence of external damage of stem (mechanical damage, winterkilling cracks) on the average velocity of sound transmission in wood, data from neighboring sensors was excluded. Different options, proposed by the software, were analyzed while result processing. The option «Use better mean value» overstates of the velocity of sound in 2 -D image, so it was we deactivated. It is necessary to activate automatic color calibration in 2 -D image for clearer picture of changes in the structure of wood in the cross-section. Then the scale will not be fixed ("floating"), that shows minimum and maximum value, found in the cross-section of wood. In this case, the red color indicates on change in the wood structure but it does not indicate decay. Therefore, option activation by the software must be considered and certain options must be selected in interpreting the results of acoustic tomography, collected by Arbotom. Methods of interpreting of the acoustic tomography results must be indicated in researches to exclude differences in results, received other researchers. 

Authors

• O.N. Tyukavina, Candidate of Agriculture, Associate Professor,
  Northern (Arctic) Federal University named after M.V. Lomonosov,
  Naberezhnaya Severnoy Dviny, 17, Arkhangelsk, 163002, Russia;
  e-mail: tyukavina@agtu.ru

Affiliation

Keywords

References

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