Acoustic Sorting Models for Improved Log Segregation


  • Xiping Wang
  • Steve Verrill
  • Eini Lowell
  • Robert J. Ross
  • Vicki L. Herian


Acoustic velocity, log diameter, log position, log sorting, lumber, modulus of elasticity, visual grade


In this study, we examined three individual log measures (acoustic velocity, log diameter, and log vertical position in a tree) for their ability to predict average modulus of elasticity (MOE) and grade yield of structural lumber obtained from Douglas-fir (Pseudotsuga menziesii [Mirb. Franco]) logs. We found that log acoustic velocity only had a moderate correlation with average MOE of the lumber produced from the logs (R2 = 0.40). Log diameter had a weak correlation with average lumber MOE (R2 = 0.12). Log vertical position in a tree was found to have a relatively good relationship with lumber MOE (R2 = 0.57). Our analysis also indicated that the combinations of log acoustic velocity and log diameter or log acoustic velocity and log position were better predictors of average lumber MOE and lumber visual grade yield than log acoustic velocity alone. For sorting best quality logs, multivariable models were more effective than the velocity-alone model; however, for sorting poorest quality logs, the velocity-alone model was as effective as multivariable models.


Aratake S, Arima T (1994) Estimation of modulus of rupture (MOR) and modulus of elasticity (MOE) of lumber using higher natural frequency of log in pile of logs II—Possibility of application for Sugi square lumber with pith. Mokuzai Gakkaishi 40(9):1003-1007.nAratake S, Arima T, Sakoda T, Nakamura Y (1992) Estimation of modulus of rupture (MOR) and modulus of elasticity (MOE) of lumber using higher natural frequency of log in pile of logs—Possibility of application for Sugi scaffolding board. Mokuzai Gakkaishi 38(11):995-1001.nASTM (2003) D6874-03. Standard test methods for non-destructive evaluation of wood-based flexural members using transverse vibration. American Society for Testing and Materials, West Conshohocken, PA.nBelsley D, Kuh E, Welsch RE (1980). Regression diagnostics: Identifying influential data and sources of collinearity. John Wiley, New York, NY.nCarter P, Briggs D, Ross RJ, Wang X (2005) Acoustic testing to enhance western forest values and meet customer wood quality needs. Pages 121-129 in Productivity of western forests: A forest products focus. Gen Tech Rep PNW-GTR-642. USDA For Serv Pacific Northwest Research Station, Portland, OR.nCarter P, Lausberg M (2001) Application of Hitmam® acoustic technology—The Carter Holt Harvey Experience. FIEA paper. In: Proceedings of the 4th Wood Quality Workshop: Tools & Technologies to Improve Log & Wood Products Segregation. Forest Industry Engineering Association, Rotorua, New Zealand, 29-30th October 2001, (August 15, 2013).'> SS, Walker JCF (2006) Variation in acoustic velocity and density with age, and their interrelationships in radiata pine. For Ecol Mgmt 229:388-394.nEdmonds RL, Cole DW (1980) Use of dewatered sludge as an amendment for forest growth. UW Bulletin No. 3. Center for Ecosystem Studies, College of Forest Resources, University of Washington, Seattle, WA.nFarrell R, Nolan G (2008) Sorting plantation Eucalyptus nitens logs with acoustic wave velocity. Technical report: Resource characterization & improvement, Project No. PN07.3018. Forest & Wood Products Australia Limited, Victoria, Australia. 27 pp.nGrabianowski M, Manley B, Walker JCF (2006) Acoustic measurements on standing trees, logs and green lumber. Wood Sci Technol 40:205-216.nHuang CL, Lindstrom H, Nakada R, Ralston J (2003) Cell wall structure and wood properties determined by acoustics—A selective review. Holz Roh Werkst 61:321-335.nIangum CE, Yadama V, Iowell EC (2009) Physical and mechanical properties of young-growth Douglas-fir and western hemlock from western Washington. Forest Prod J 59(11/12):37-47.nMora CR, Schimleck LR, Isik F, Mahon JM, Clark A III, Daniels RF (2009) Relationship between acoustic variables and different measures of stiffness in standing Pinus taeda trees. Can J For Res 39:1421-1429.nRoss RJ, McDonald KA, Green DW, Schad KC (1997) Relationship between log and lumber modulus of elasticity. Forest Prod J 47(2):89-92.nSonne EC (2001) Biosolid fertilization and thinning influences on stem form, log and lumber quality, and value: A case study for mature Douglas-fir stand. MS thesis, University of Washington, Seattle, WA. 76 pp.nTsehaye A, Buchanan AH, Walker JCF (1995) Stiffness and tensile strength variation within and between radiata pine trees. J Wood Sci 13(5):513-518.nTsehaye A, Buchanan AH, Walker JCF (1997) Log segregation into stiffness classes. Pages 7-10 in BG Ridoutt, ed. Managing variability in resource quality. FRI Bulletin No. 202. Forest Research Institute, Rotorua, New Zealand.nTsehaye A, Buchanan AH, Walker JCF (2000) Sorting of logs using acoustics. Wood Sci Technol 34:337-344.nWang X (2013) Acoustic measurements on trees and logs—A review and analysis. Wood Sci Technol. 47:965-975.nWang X, Ross RJ, Brashaw BK, Punches J, Erickson JR, Forsman JW, Pellerin RF (2004a) Diameter effect on stress-wave evaluation of modulus of elasticity of small-diameter logs. Wood Fiber Sci 36(3):368-377.nWang X, Ross RJ, Green DW, Brashaw B, Englund K, Wolcott M (2004b) Stress wave sorting of red maple logs for structural quality. Wood Sci Technol 37:531-537.nWang X, Ross RJ, Carter P (2007) Acoustic evaluation wood quality in standing trees. Part 1. Acoustic wave behavior in standing trees. Wood Fiber Sci 39(1):28-38.nWWPA (1998) Western lumber grading rules. Western Wood Products Association, Portland, OR.n






Research Contributions