Ultrasonic wave velocity as a moisture indicator in frozen and unfrozen lumber

This study investigated whether ultrasonic wave velocity can be used as a measure of the moisture content (MC) in frozen and unfrozen spruce lumber. Experiments to determine ultrasonic wave velocity in the radial direction were conducted at five different MC levels. The results show that a strong inverse relationship exists between ultrasonic wave velocity and MC in both frozen and unfrozen lumber. The wave velocity in frozen wood was consistent and about 5 percent greater in frozen wood than in unfrozen wood. The relationships existed both above and below fiber saturation and the differences were statistically significant. While the main research effort centered on the differences in wave velocity between frozen and unfrozen wood at specific MC levels, a study was also done to determine the effect of temperature on ultrasonic wave velocity. Ultrasonic wave velocity decreased linearly with increases in temperature. The findings of this study suggest that ultrasonic wave velocity can be applied as a moisture indicator in either frozen or unfrozen lumber.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member