Enhancement of Malaysian structural timber grading using dielectric sensor

Strength grading of structural timber is important to enhance the value of the timber. This circumstance conveys that demands of non-destructive testing and evaluation techniques to estimate the physical and mechanical properties of timber structures need to be enhanced. In this paper, research work focuses on the development of dielectric sensor to measure electromagnetic properties (dielectric constant) of timber in low frequency range I kHz to 100 kHz. A mobile dielectric sensor has been developed. One hundred and fifty nine timber samples were graded using Malaysian visual grading standard. These samples were chosen from six different Malaysian timber types representing three selected strength grade. The experimental results for dielectric properties, bending strength, compressive strength and modulus of elasticity of timber samples were reported. The effects of frequency, timber type and timber grade on timber dielectric properties were discussed. The use of the measured dielectric constant shows the ability of the sensor which has been developed in this study to enhance the visual grading of timber material.