We have received several reports from our users telling us that they cannot pair their ArborSonic3D with a Windows 11 PC.
The reason behind this is that Windows 11 has introduced a new Bluetooth setting that, on its default setting, prevents the pairing of classic Bluetooth devices.
Limitations: acoustic shortcut, ring shake, deep crack visualization
January 19
Acoustic tomography and biomechanics
Interpretation of acoustic tomographic image, biomechanical interpretation
Mechanical stresses in tree: compression, bending and shear
Wind load calculation
Bending stress from wind load and tree leaning
Compression stress from self-load
Safety factor calculation and interpretation
January 22
Acoustic tomography for ArborSonic3D users, new features in the software
Ludwig sensors
GPS data
Controlling the self-calibration algorithm
New warning in case of low velocities
Low Energy Bluetooth capabilities for new hardware
Limitation in the Android software
January 24
Pulling Test basics: Possibilities and limitations
Pulling test inclino-method for root investigation
Pulling test elasto-method for trunk investigation
Evaluating the correctness of the fit between the measured and generalized uprooting curve
Reasons for a poor fit (wind, loose inclinometer, too fast pulling, root failure)
Correction of the raw data in case of a poor fit
January 26
Pulling test: The uprooting curve
Importance of the root investigations, failure mode statistics: breakage of trunk versus uprooting failure
Principle of the pulling test
How many inclinometers are necessary?
Uprooting curve, uprooting test
Verification of the uprooting curve
Lower limit of the minimum inclination for a measurement to be meaningful
Upper limit of the inclination during the measurement
Effect of the soil moisture content on the safety factor
January 29
Acoustic root detection
Principle of the acoustic root detection
The acoustic root detection procedure
Velocity limit setting
Distance between test points
Visualization of the result
Recommended application and limitation
January 31
Dynamic version of the pulling test: DynaRoot and DynaTree
Pulling test limitations: static/dynamic load, anchor point availability, vertical load
Solution: Using wind as loading “device” and consequences
Requirements for sensors
Chaotic nature of wind and tree interaction
Statistical window width
Visualization of the test result
Safety factor calculation
February 2
DynaRoot and DynaTree users’ meeting to share experience
Case studies indicating of the importance of
wind direction
location of the anemometer
the minimum wind speed requirement
We are inviting feedback from DynaRoot/DynaTree users:
short user presentation about interesting/strange test result: a short PowerPoint presentation or simple explanation of the experience
organization of the workflow with regards to wind dependencies
finding good/acceptable anemometer location
Wind direction dependency in Dynamic root testing
The encircled Eucalyptus sp. tree was tested over several days at high wind velocity during February 2022 with DynaRoot dynamic root testing system. The tree is approximately 17 meters tall and has a diamater of 44 cm at breast height. The measurements were conducted in the United Kingdoms by Mr. James Chambers, Tim Moya Asssociates.
Eucalyptus sp.
Inclinometer
Anemometer
Location
The image on the left shows the satellite image of the surrounding area of the measured tree. The red cross indicates the tree in question, while the yellow cross indicates the location of the wind anemometer. It is clearly visible that the tree is protected from the wind from the south, southwest and southeast by several large buildings, while completely exposed to the wind in any other direction.
Measurements
Date
max. wind speed (km/h)
wind direction (degree)
Safety Factor
correlation
Oct. 27
84
340
0.94
0.95
Feb. 18/1
113
208
3.96
0.94
Feb. 18/2
119
260
0.96
0.95
Feb. 18/3
53
243
1.24
0.72
Feb. 19/1
72
259
1.1
0.82
Feb. 19/2
68
221
2.89
0.76
Feb. 20
72
215
2.89
0.72
Feb. 20/1
94
281
0.92
0.85
Feb. 20/2
50
307
0.84
0.68
The table above shows the measured speed and the direction of the wind, with the corresponding Safety Factor calculated by the software. The results show that from protected directions (S,SW,SE) the Safety Factor is significantly higher. From unprotected directions (West ~ 260°, NW ~ 340°) the Safety Factor is below 1 which is deemed unsafe by the software. On the right the arrows indicate some of the wind directions.
The graph shows that after the change in wind direction (red line) the inclination measured on the tree became significantly higher.
Conclusions
Ultimately as the gathered data shows, the results of DynaRoot is highly influenced by wind direction. It is extremely important to always take the wind direction into consideration when evaluating DynaTree measurements. When a high Safety Factor is due to the tree being shielded from the wind (by other trees, buildings), it is recommended to repeat the measurement in unobstructed wind.
Pulling test: The effect of cut roots on safety factor
A brief case study by Tibor Horvath with Fakopp Pulling Test
Conditions
The measured tree stood in a suburban garden and has been marked for removal.
The removal has been turned into a series of 6 pulling tests. First we measured the tree in its original state, then before every additional pulling test some of roots have been cut.
For the calculation of the safety factors, the wind speed of 33 m/s (cc. 120 km/h) has been used.
The purpose of the experiment was to reveal the effect of cut roots on the safety factor.
Safety factor measurements
Intact: 1.19
Excavated: 0.86
1 root cut: 0.61
4 roots: 0.33
7 roots: 0.27
All 11 roots: 0.14
Results
Ludwig sensor test of a Platanus occidentalis
A Platanus occidentalis tree has been selected for examination in a botanical garden (Sopron, Hungary). First the measurement has been conducted with 12 regular sensors and then with an additional 12 Ludwig sensors.
The first measurement using 12 regular sensors shows a decayed area in the middle (about 40%).
The second measurement with additional Ludwig sensors shows a decayed area in the middle (about 32%), and also a strengthened area on the side near sensors 9-12.
The tree suffered a freeze injury several years ago. This is exactly the part where the strengthened wood has been found.
