The CRC for Forestry has discovered that acoustics can be used to accurately measure certain wood quality parameters, with little effect on harvester productivity.

The research results were published as Bulletin 25 (May 2012), and the title is “Evaluation of the Hitman PH330 acoustic assessment system for harvesters”. The authors were D Walsh, S Ardile, and P Carter. Acoustic technologies can predict the stiffness or modulus of elasticity (MOE) of wood. Being able to predict the MOE when logging is beneficial, as the log can be directed towards the sawmilling process that obtains the best value from it. The studies were carried out in Pinus radiata sawtimber plantations.

Fibre-Gen developed a machine-mounted acoustic measurement system, the Hitman PH330, which can be retrofitted to a Waratah 624 or 626 harvester head. The PH330 contains two hydraulic probes which are inserted into the stem when the crosscut saw is activated. When the saw retracts, the PH330 takes a measurement and the probes retract (1.5 seconds later) and the feed rollers are activated. The logs produced were analysed at the mill.

The results showed that the PH330 could accurately predict the MOE. There was no measurable reduction in harvester productivity due to the measurement of the MOE during crosscutting. The productivity drop of 4.2% was not significant, but could possibly be reduced by integrating the PH330 with the harvester’s on-board computer.

For more information contact Mark Brown at mbrown2@usc.edu.au, and consult the CRC website at www.crcforestry.com.au