You have no doubt heard about or even experienced the use of ultrasound in medical diagnosis. It is also widely used in science and industry for a wide range of purposes ranging from pure research to industrial quality control. 

In 1997, our laboratory developed and built probably the first such device to be used in the examination of art objects. Our objective was the investigation of the internal structure of wooden objects, to detect hollow cavities and to evaluate the condition of the wood deep inside the specimen. Such information is valuable in establishing the state of conservation of wooden sculptures, picture frames and furniture. 

Since sound waves are scattered, reflected and refracted in a solid elastic medium, the internal structure of the object can be evaluated. As a pulse is sent out and enters the specimen, its speed is changed by the structure and density distribution of the object being examined. In fact, the speed of sound changes drastically depending on the orientation of the wave to the grain of wood. Knots, cracks, delaminations, inclusions, cavities, corner and edge reflections reveal themselves extremely well.