Estimation of mass and moisture content of flat square lumber in a stack during air-drying process by the vibration method with additional mass

Abstract

A vibration test to measure the mass of a specimen without weighing it using the difference between the resonance frequency with an additional mass and that without it (vibration method with additional mass, VAM) was applied to Japanese cedar flat square lumber with dimensions of 210 mm × 135 mm × 3000 mm both with and without a pith in the process of air-drying. The longitudinal and bending vibration tests were performed on the specimens with and without an additional mass. The accuracy of VAM that was expressed by the estimated mass by VAM to the measured mass (MVAM/M0) was sufficiently high throughout the air-drying process. The accuracy of VAM for the longitudinal vibration was higher than that for the bending vibration. The moisture content based on the estimated mass by VAM was in the expected range.