Articles
STANDING TREE QUALITY ASSESSMENTS USING ULTRASOUND
In the forest, they are associated together in the eco-system.
In the cities, they act singly in ecological and decorative functions.
Quality assessments of standing trees may be considered to have two separate targets: biological internal quality related to wood degradability and elastic quality of the heartwood regarding the industrial valuation of the wood products.
Biological internal quality of standing trees can be non-destructively evaluated using ultrasound.
The speed of a low frequency wave propagated on the radial axis of the tree is measured.
Compared to a referential speed for each species, deviation of the speed is considered to be indicative of degraded wood.
Diameter and seasoning effects must be taken into account for better accuracy of the diagnostics.
Elastic quality of the wood contained in the tree can be evaluated by ultrasound.
In this application, speed of sound is measured on the longitudinal axis in the sapwood area.
Dispersion of the results in terms of speed is the basic information allowing a first step in grading the internal wood material.