Description of what it is and means
- Researchers are discovering that the stiffness of trees is most important in determining how timber grades at the sawmill.
- Microbifril angle is well correlated with wood stiffness.
- Acoustic Velocity is a non-destructive indirect assessment of microfibril angle.
- Sound travels between two probes knocked into the tree via the microfibrils in the wood. If they are straight (good, stiff timber) the sound travels very fast; if they are at an angle (bad, less stiff timber) the sound travels slower. The units of measure are km/sec.
- Due to cost of assessment restrictions we tend to only measure families we are interested in for other reasons, and of course the QCI control which is standard yard-stick.
What does it mean
- All data are presented relative to the QCI control. For example QCI = 4.0 km/sec and the selected family is 4.2 km/sec, the selected family is thought to be stiffer (better AV) by 5%
- The SSBC is working on increase the AV database.