Successiv uttorkning av stockar – inverkan på akustisk mätning av elasticitetsmodul

The current study explores the effect of summer storage on the modulus of elasticity measured with acoustic technology. The 36 saw logs used in the study, were selected to represent logs with low- and high MOE, and were also measured for a range of other properties such as log taper, knots, growth ring width data, compression wood, and basic density on discs cut from the top- and butt end of each log. The water loss during the two month summer storage caused lower log density. Although the measured resonance frequency and the calculated MOE therefore increased, the ranking in MOE between logs was not much affected. When the real log density was considered the change in MOE became insignificant. The MOE of logs, with and without correction for log density was found statistically correlated with several of the measured wood and log properties. The study utilised a test sawing in order to study the agreement between log MOE and the MOE of the lumber sawn from logs. A clear agreement was seen between the lumber construction quality and the MOE of logs. That is, logs with high MOE generated a higher proportion of high quality lumber compared with the lumber cut from low MOE logs