We at Arbor Cultural Ltd. have invested in a new IML RESI-PD400. This specialist instrument is designed not just for accurate measurement of the resistance given by wood to drilling (torsional resistance), but also an accurate measurement of the pushing force required to penetrate the tree stem.
This can be used as a tool to determine the strength loss of a stem or branch, to help determine whether it can be retained and whether any form of tree surgery is required.
Resistance to drilling by wood is not a complete measure of wood strength, but resistance is usually significantly reduced if the wood is weakened by decay.
The additional measure of the pushing force incorporated into this new device is important as it assists in the measurement of some structural loss due to certain types of decay, which were not so evident from just the rotational measurement.
Both of these readings are displayed on a digital readout on the top of the device, which can be exported as a graphical image into a report.
This device is used to excavate a narrow penetration track with a fine drill where decay is suspected. The IML RESI-PD400 has a drill diameter of approximately 3mm and a drill length of 400mm.
The RESI drill bit causes minimal damage as it is of small diameter which leaves a narrow penetration track. It also does not remove the wood fragments when extracted.