A new system for checking the quality of wood involves vibrating it at a rate of 20,000 times per second
When choosing wood for applications such as load-bearing beams in houses, it's important not to use pieces that contain cracks or other defects that could affect their structural integrity. While not quite as crucial, it's also nice to avoid flaws when building things like wooden furniture, piano soundboards, or window frames. Typically, people have been limited to visually checking the wood for such defects. Now, however, researchers at Germany's Fraunhofer Institute for Wood Research have developed a system that highlights faults invisible to the human eye, using a process called high-power ultrasound thermography.