AEMG recently completed decay detection on several trees for University of Birmingham. Picus® Sonic Tomography system and Resistograph® drill were used to highlight the amount of decay within the trees. Picus® Sonic Tomography system measures the time sound waves take to go through the tree. Picus® system uses low frequency sound to measure the density of the wood inside the tree. The data produced from twelve separate sensors is converted into a four colour image representing a cross-section of the tree at the selected measurement height. Picus® scans help support the justification of retaining trees that are important in the landscape. The full extent of the decay can be quantified instead of assuming the extent of the decay. The above image shows the tomograph that is produced. This tree has a large area of decay, the Picus scan shows 56% decay or cavity / 28% sound wood / 16% altered wood. This tree has a Moderate risk rating of stem failure, therefore it has been recommended for a 15%-20% crown reduction. Without this technology this tree may have been felled.
IML ResiPD500 (Resistograph®) is an electrically powered micro-drill which measures the drilling resistance of the wood and represents the collected data digitally as a measurement curve or graph. The above image shows the produced graph. From right to left is the direction of the drilled wood. The first 7cm indicate sound wood, for the following 16cm the graph indicates advanced decay, the remainder of the graph from that point indicates a cavity/hollow. This Ash tree has a Very high risk rating of stem failure and has been recommended to be felled Immediately. Without this technology the significance of this decay may not have been realised.