珍贵老树之非破坏性检测技术与案例

本报告简介常用之树木非破坏检测仪器，并应用3D声学断层影像技术检测肖楠圆盘上凿洞方式，人工模拟各种孔洞大小及针、阔叶树天然腐朽情形，并进行野外3株老树实地检测。发现FakoppArborSonic3D声学断层影像对木材内部缺点定位能力颇佳，但无法精确描绘出空洞之形状，其量化结果有稍为高估情况。但增加检测头可提高判定腐朽或各项缺点之精度。弦向和径向音速之比值与孔洞率大小有密切关系，可为快速评估立木有无空洞腐朽的检测方法。由检测结果证明，Fakopp声学断层影像，对树干内部腐朽空洞之评估，搭配ArborSonic3D软件为有效之工具。

The technique and examples of nondestructive evaluation on giant standing trees

The purpose of this report was to introduce nondestructive evaluation （NDE） of stand trees and to apply a 3D acoustic tomography inspection through the simulated decay with various types and sizes of artificial holes on the Taiwan Incense Cedar （ Caloce＆ws formosana） discs and natural decay d coniferwood and hardwood. Moreover, we inspected old and giant stand trees by 3D Fakopp ArborSonic stress in the field then compared the actual hole or de- cay situation with the estimation by 3D Fakopp ArborSonic acoustic tomography. The results showed that a better ca- pability in positioning internal holes on the disc was found by using a 3D acoustic tomography. But the shape of the hole was not able to be depicted accurately and the quantitative results showed over a little estimation as well. Howev- er, we could improve the estimated accuracy by increasing more sensors. Furthermore, there was a significant rela- tionship between R/T ratio of stress waves and hole size which co~d be used as a preliminary inspection for the rapid detection on the decay and hole internal standing trees. Therefore, matching ArborSonic soft wares was a good instru- ment of acoustic tomography for inspecting the internal stem.