Often as part of a tree survey, features such as areas of decay cracks or cavities can be found, and this can raise doubts in the mind of surveyors, tree workers and owners.

Arboricultural surveyors should undertake further assessments of these features when the tree location, history or targets requires this - gone are the days of just sounding a tree with a hammer!

At Barnes Associates Ltd we have years of experience and are often called upon to provide a second opinion to other surveyors as we have a wide range of devices that enable us to assess the interior of a tree without the need to drill, which can cause significant damage.


Basic information can be provided by simply recording the time taken for a sound wave to travel across a stem using a Microsecond Timer. Comparison of the predicted time based upon the known species and distance between the sensors can provide valuable information on the extent of decay or the location and depth of cracks. This is really useful tool for climbing inspections.

For more detailed assessment we take the principal of speed of sound moving in wood and apply this to multiple sensors arranged around the stem in a process known as Sonic Tomography, using an Arborsonic 3D Tomograph. This system produces an image to represent the speed of sound and from this we can get information on the location and size of defects and by adding multiple layers we can begin to understand the three-dimensional aspect of decay in a tree.

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