Electrical resistance characteristics of thermally modified wood

Abstract

This paper presents electrical resistance characteristics of ThermoWood® Thermo-D Norway spruce for wood moisture content measurements below fibre saturation point. Electrical resistance along the grain of small clear wood specimens was measured at various moisture content levels of ~ 4–15% for thermally modified and ~ 5–25% for unmodified spruce. The results show that—similar to unmodified wood—the relationship between wood moisture content and electrical resistance can be well described by a first order polynomial function obtained from simple linear regression. This provides accurate resistance-based predictions of thermally modified wood moisture content. In addition, established temperature corrections derived previously from unmodified wood seem applicable to thermally modified wood.