Development of dynamic moisture content measurement system for wooden members exposed to fire heating

Abstract

Abstract In this study, a small sensor for the dynamic measurement of the local moisture content within a wooden member exposed to fire heating is developed. The measurement is based on the unique dependence of the electrical resistance of wood on moisture content and temperature. These relationships are observed experimentally at temperatures between 20°C and 90°C, and moisture content between 6.9% and 232.8%, for Cryptomeria japonica, Larix leptolepis, Pseudotsuga menziesii, and Zelkova serrata. The electrical resistance is represented with the temperature and moisture content for each tree species. The measurement is found to be the most effective within the moisture content of 10%‐30%.

Keywords

• electric resistance
• heat and water transfer
• mechanical property
• moisture content sensor
• wooden members