Sylvatest

Sylvatest is an acousto-ultrasonic measuring device that provides an overall diagnosis of the wood element, based on the speed and energy absorption of the transmitted ultrasonic wave.^[1][2][3] The result given reflects the residual health of the wood in the trunk of the tree tested or the beam measured. These are non-destructive tests.^[4][5]

The technology was developed by Professor Jean-Luc Sandoz as part of his thesis at EPFL in 1984.^[4][6]

Non-destructive ultrasonic testing of wood is a method used to assess its mechanical properties, particularly the modulus of elasticity in different directions. It is based on measuring the propagation velocity of sound waves through the material and the density of the wood.

An ultrasonic wave is emitted through a wood specimen using a transducer (sender) placed at one end. It is received by a second transducer (receiver) at the opposite end. The transit time is used to calculate the propagation velocity V of the wave through the material. This velocity is directly related to the mechanical properties of the wood.

The propagation velocities of ultrasonic waves in a material, such as wood, are directly related to its mechanical properties and density.

Longitudinal (VL) and radial (VR) wave speeds can be expressed as:

${\displaystyle V_{L}={\sqrt {\frac {c_{L}}{\text{density}}}}={\sqrt {\frac {E_{L}}{\text{density}}}}}$

${\displaystyle V_{R}={\sqrt {\frac {c_{R}}{\text{density}}}}={\sqrt {\frac {E_{R}}{\text{density}}}}}$

• density is the material's mass per unit volume.

These relationships are commonly used in non-destructive testing (NDT), particularly in ultrasonic transmission techniques, to assess the internal mechanical condition of wood and other materials.