PICUS Sonic Tomography - Non-Invasive Decay Detection

We employ the latest non-invasive equipment to assist with decay detection in trees. This includes the PICUS Sonic Tomograph, which we have owned since 2003, and has proved to be an extremely useful tool in helping to make informed decisions regarding tree safety.

The PICUS measures the time taken for sonic stress waves to pass through the wood of a tree between sensors that are placed at a predetermined level around the tree stem.

The differing velocities of these waves help determine the wood density of a cross-section of the tree (sound waves generally travel faster through sound wood than through decayed wood). These velocities are then calculated and interpreted to produce a colour image of the internal decay patterns.

We then analyse the results and provide a report with recommendations. We have carried out over 500 tomograph surveys in the past ten years and are experienced at interpreting the results, specifically with regard to the species of tree and fungal decay present.

London plane with basal heartwood decay Tomogram of London plane with basal heartwood decay

This London plane had a small basal cavity and a swollen lower stem (indicating the possibility of internal decay). A tomograph survey confirmed extensive basal heartwood decay (blue/pink shading).

PICUS Sonic Tomogram of beech tree with Kretzschmaria deusta infection Felled beech tree with Kretzschmaria deusta infection

Tomogram and cross section of felled beech with Kretzschmaria deusta infection