JERRY DICKER BA (Oxon), DTEO (Man), Tech Cert (Arbor A)
58 High Street, Thornbury, BS35 2AN, Phone 01454 416945 Mobile: 07798 741872
Email : jerry@treesjerrydicker.co.uk
Trees - Home Picus Tomograph How it works Clients Courses Example 1 Example 2

TREE DECAY DETECTION WITH THE PICUS SONIC TOMOGRAPH

The Picus uses the fact that the velocity of sound in wood depends on the modulus of elasticity and the density of the measured wood. Most types of damage which impair safety by increasing the likelihood of fracture - in particular cavities, white rots and brown rots - reduce elasticity and density in the wood

PROBLEM WITH FORMER SONIC ASSESSMENTS

These wood characteristics vary both within a tree species and between tree species. Comparing individual sound velocities, measured on a specific tree, using tabulated values, only detects extensive damage.

RELATIVE SOUND VELOCITIES

The Picus therefore uses relative sound velocities so that the system calibrates itself automatically at each measured cross-section.

RELATION OF THE COLOURS TO THE SOUND VELOCITIES

The colours shown on the tomogram are determined at the point at which two paths intersect. Areas with no intersection paths are classified according to the nearest confirmed intersection.

GREEN

Green areas, although of lower density in comparison to the brown areas, may not necessarily be decayed. Included bark etc may also show green, as well as the areas of degraded wood around more extensive zones of decay which show as purple or blue.