In situ measurement of wood moisture content in high-temperature steam

Changes in moisture content of sugi (Cryptomeria japonica D. Don) wood during high-temperature saturated and superheated steam treatments were investigated. A system for in situ weighing of specimens was used, and the reduction of wood substance by heating was taken into consideration. At 160degreesC the loss of wood substance due to heating was significant and influenced the moisture content values, but it was almost negligible at 120degreesC. Treatment time and temperature affected the moisture content in saturated steam but not in superheated steam. Excess water in a saturated closed system appears to promote the decomposition of wood and condensation in or on specimens.