Nondestructive research on wooden musical instruments: From macro- to microscale imaging with lab-based X-ray CT systems

X-ray CT scanning is an invaluable technique in many research domains. Different commercial scanner types are developed, tailored to different needs, yet the Centre for X-ray Tomography of the Ghent University (UGCT) develops its own in-house open modular scanners with significant experimental freedom, both for applied research in various fields as for research on tomography itself. The maturity of the technique opens up possibilities in cultural heritage, more specifically the field of wooden musical instruments. Here, we present the possibilities and opportunities of two particular scanners at UGCT: Nanowood and HECTOR. Instruments of different size and shape can be scanned either entirely either one can focus on a specific region of the instrument, resulting in qualitative and quantitative mapping of a range of features at different spatial scales. A cello, acoustic guitar, violin and bow, pipa and standard recorder are scanned using different acquisition modes, and qualitative and quantitative assessment of different features such as general structure assessment, glue line integrity, thickness distribution mapping, volume calculations, growth ring analysis are illustrated. These examples demonstrate the flexible and powerful use of lab-based CT scanners for nondestructive research of wooden musical instruments.