An Ultrasonic System for Detecting Defects in Wood

Sallehuddin Ibrahim, Wasi Hyder, Mohd Amri Md Yunus, Ahmad Ridhwan Wahap, Ruzairi Abdul Rahim, Jaysuman Pusppanathan

Abstract

This paper aims to describe a low cost ultrasonic system which can distinguish between good and defective woods. In this preliminary investigation, two samples of wood from the acacia species are chosen. The defects in the wood can be detected by the system without damaging the wood. A low cost 40kHz ultrasonic system has been successfully developed for this purpose. Two 40kHz ultrasonic transmitter and receiver transducers configured based on the through transmission technique are used to evaluate the strength of the wood. The acquired data is later transferred to the MATLAB software for signal processing. The analyses based on SNR and cross-correlation of the received signal evaluated the Modulus of Elasticity of the sample in the longitudinal direction. The results show that the ultrasonic system has the capability of distinguishing between a good wood and a defective wood