Complex Dielectric Properties of the Sapwood of Aspen, White Birch, Yellow Birch, and Sugar Maple

Abstract

The dielectric properties of four Canadian eastern wood species were measured as a function of moisture content and temperature, at frequencies between 0.4 and 2.47 GHz using the cavity perturbation technique. The temperature was varied from − 20 to 58°C and moisture content from 40 to 136%. Dielectric properties varied with moisture content, wood temperature, and microwave frequency. However, the influence of moisture content and microwave frequency overshadowed the influence of wood species and wood temperature. The dependencies were established for the selected species and discrepancies are discussed, namely concerning their implication when used in wood industry (nondestructive testing, heating, and drying).

Keywords:

• Dielectric properties
• Drying
• Microwave frequency
• Moisture content
• Wood

ACKNOWLEDGMENTS

The authors are thankful for the Canada Research Chair Program and the Ministère du Développement Économique l'Innovation et de l'Exportation (MDEIE), Québec for funding.

Notes

∗d_p in cm.

∗d_p in cm.