1. The document discusses using advanced sonic technology tools to measure wood stiffness in logs. This allows log scalers and customers to optimize value from wood processing. 2. Key applications of measuring wood stiffness include sorting logs for veneer and structural lumber to increase yields. Trials show stiffness sorting can increase high grade yields by 10-20%. 3. The document reviews factors that influence wood stiffness measurements, including log age, position in tree, temperature, and moisture content. This information helps interpret stiffness readings and maximize their value.

1. 1
HITMAN
Advanced Sonic Technology
for Log Scalers
and their Customers
Timber Measurements Society Meeting
October 17-18 Longview,Washington, USA
Peter Carter – Chief Executive, Fibre-gen
Presented by Andy Dick – MD, Logjiztix

2. Business Results – Sonics enabled
• Measure Wood Quality before processing:
– In conjunction with scaling in mill yard for LVL and
MSR
• Forecast actual mill LVL or MSR lumber out-
turn from log supply
• Reduce waste and lower processing costs
• Reliably fulfill sales orders
• Improve profitability through process
optimisation

3. 3
Portable tool for log scaling application
LG640 Automated tool also available for log scaling application

4. • Stiffness = density x (velocity)2
• Velocity is derived from resonant
frequency (2nd harmonic) and length
• Sensor/microphone detects frequency
from hammer blow
• Green density is relatively constant
HM200 & LG640 – how they work
3.3
length
velocity = 2 x length / time
stiffness densityx velocity≈ 2

5. Customer values are high - Veneer
Douglas Fir trials - sorted the log infeed at a 13,000ft/sec threshold.
Increase Yield of Veneer – 2 operational trial results:
1. 62% Yield of G1&G2 compared against 47% unsorted logs
2. 60% Yield of G1&G2 compared against 45% unsorted logs
Lodgepole pine trial results
• 0.1km/sec improvement in sonic velocity is worth US$16/m3
• US$3.8m for a 300,000 t mill (at US$250/m3 for G1 veneer)
Measuring and managing stiffness will increase profit
Scaling is a key opportunity to measure and add value

6. • MSR vs Standard or better lumber price differential
US$15/m3
• Average log infeed velocity improvement of 0.2km/sec
will increase MSR YIELD from the mill by 10%
This equates to:
• US$450,000 for a 300,000 m3 mill
Measuring and managing stiffness will increase profit
Scaling is a key opportunity to measure and add value
Customer values are high - MSR

7. 7

8. • Sonic measures provide valuable log quality
information for your customers
• Wood stiffness in logs is a key measure for
LVL veneer and MSR lumber manufacturers
• Tools are available to quickly and easily
measure stiffness at time of scaling
• Stiffness information measured at this time
is key for value optimisation from
subsequent processing
Conclusions – Log Scaling

9. For further information
peter.carter@fibre-gen.com
www.fibre-gen.com

10. Further detail for implementation

11. • Acoustic velocity generally increases with increasing age
• 0.06 Km/s increase on average per year
• Velocities do still vary widely within an single Age class
• Strategy - harvest highest Velocity rather than oldest age
Velocity variation with Age
Log age vs. average acoustic velocity
R
2
= 0.66
2.50
2.60
2.70
2.80
2.90
3.00
3.10
3.20
3.30
3.40
3.50
18 20 22 24 26 28 30 32 34
Log age (years)
Stand
Linear (Stand)
VelocityvsStand Age
2.80
2.90
3.00
3.10
3.20
3.30
3.40
3.50
3.60
3.70
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
Age (years)
Velocity(km/sec)
Mean Velocity (50% oldest age) = 3.43
Mean Velocity (50% highest V) = 3.37
Benefit = 0.06km/sec

12. Velocity variation Butt Log to Top Log
• Acoustic velocity varies from butt to top
• Highest velocity logs are in mid section of
stem – log 2 & 3
Radiata Pine - Log velocity within stem
2.50
3.00
3.50
4.00
0 5 10 15 20 25 30
Distance upstem(m)
Velocity(km/sec)
Average 3.2 km/ sec
Average +2 x SD
Average -2 x SD
Stand Mean 3.2

13. Velocity variation – Pith to Bark
Average stiffness of lumber cut from
some 60 trees. Note the low stiffness at
the base of the tree, in the butt logs.
Why not cut a short, 2.5 m butt log?
1st log 2nd log 3rd log
Ping Xu, 2002 Source: J Walker, University of Canterbury

14. Velocity variation with Temperature
• Acoustic velocity increases with lower temperature
• Rate of change defined best in Swedish log study
• Moisture content changes may compensate on logs,
but not in trees
Temperature Effect on Acoustic Velocity of Green Board
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
-20 -15 -10 -5 0 5 10 15 20
Board Temperature (C)
AcousticWaveVelocity(m/s)
Stack 6 (50 boards)
Stack 2 (50 boards)
V = 2365 - 17.69T (T ? 0 °C)
V = 2365 - 41.42T (T ? 0 °C)
Density(MC) adjustedacousticspeed
2
2.5
3
3.5
4
4.5
5
-25 -20 -15 -10 -5 0 5 10 15 20 25
Series1
Series2
Series3
Series4
Series5
Series6
Series7
Series8
Series9
Series10
Series11
Series12
Source: L Bjorklund, VMR, SDCSource: P Harris, IRLSource: X Wang, University of Minnesota

15. Velocity variation with Moisture Content
• Acoustic velocity varies with moisture content
• MOE = Green Density x Velocity2
• Therefore green density decrease is
proportional to increase in V2
• Potential application
– MC of Beetle killed wood