Acoustic wave propagation testing to determine quality in timber and timber products

Abstract

Assessing and grading of raw materials in the timber industry is a key factor in the maximization of extracted value. Several different approaches are utilized to measure the quality of standing timber and sawn lumber. Assessments typically involve physical measurements, but have evolved to include non-destructive evaluations, machine strength rating and acoustic wave-length assessments to predict the strength potential and overall value of timber more accurately. This report explores acoustic testing methods to determine qualities associated with standing and raw timber properties, such as strength, hardness, and density, which ultimately impact the value of wood products and how wood mills efficiently utilize and market their wood products. Results gathered in acoustic studies are conflicting when presenting correlations between wave propagation and density, but most agree that targeting specific species in proper temperatures generates consistent results. Acoustic testing is less effective on standing timber when compared to whole log timber where two faces are present for testing. Applications of acoustic technologies at all stages of the wood supply chain could considerably increase the utilization of forests products. These applications include the use of handheld technologies used by technicians and technologists, processing heads in harvesting operations and on mill sites before the sawing process begins.