Detection of acoustic velocity and electrical resistance tomographies for evaluation of peripheral-inner wood demarcation in urban royal palms

Abstract The material properties and thickness of peripheral wood of royal palms have significant impacts on in-situ structural safety. Stress wave velocity ( V ) and electrical resistance (ER) tomograms were detected in royal palms ( Roystonea regia ) for understanding the soundness and standard values of the peripheral region. The position of the peripheral-inner wood demarcation was measured using drilling resistance profile from living trees and the corresponding V and ER of the peripheral-inner wood boundary was acquired respectively from V and ER maps. The two parameters V and ER of the peripheral-inner wood demarcations were linearly related to the results obtained from tomogram. Furthermore, the positions of the peripheral-inner wood demarcation were determined by corresponding V and ER, and the critical V and ER can be established by average V and ER of tomographic data. The experimental results from this study indicated that V and ER tomogram techniques can be employed to determine the position of the peripheral-inner wood boundary and can serve as a technique to determine the structural stability status of living palms.