Abstract
Non-destructive techniques (NDTs) are well suited for rapid estimation of timber properties, but NDT results are affected by several factors, the most important of which is the moisture content (MC) of wood. Much of the research in this context was limited to ultrasound measurement of a few wood species, mainly to Norway spruce. The present paper investigates the MC influence on the NDT results obtained by instruments based on ultrasound (two devices), impact stress waves (one device) and longitudinal vibrations (two devices). A hundred large cross-section specimens of four timber species were tested, namely: radiata pine, Scots pine, Salzmann pine and maritime pine. The influence of MC on velocity was found to be stronger below the fiber saturation point (FSP) than above FSP. MC adjustment factors below FSP are proposed for these wood species.
Acknowledgments
Ministerio de Economía y Competitividad [Spanish Ministry of Economy and Competitiveness]. Plan Nacional I+D 2013-2016. Proy.: BIA 2014-55089-P. Plan Nacional I+D+i 2008-2011. Proy.: BIA 2010-18858. The authors would also like to thank Mr. Ramón García Lombardero for his technical support in the Forest Products Department Laboratory of INIA-CIFOR, Spain.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Employment or leadership: None declared.
Honorarium: None declared.
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