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Nondestructive assessment and imaging methods for internal inspection of timber. A review.

  • Konrad J. Vössing EMAIL logo and Ernst Niederleithinger
From the journal Holzforschung


This paper reviews state-of-the-art in nondestructive testing (NDT) and semidestructive testing (SDT) methods applicable for imaging the condition of structural timber. Both NDT and SDT imaging reveal defects, damages, and decay, while the extent of wood decay can also be quantified. Combined with an appropriate data interpretation concerning the internal defects, the mechanical properties of the material can also be assessed. The possibilities and limitations of the most relevant individual NDT and SDT methods, also in combination with each other, are outlined and compared. To facilitate comparison, many observations are reported based on the same test specimen.


The research work was subsidized by the Cusanuswerk, Episcopal Study Sponsorship. The authors would like to express their gratitude to Marcel Grunwald from the Federal Institute for Materials Research and Testing, Berlin and Reinhold Herschel from the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Wachtberg.

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: None declared.

  3. Employment or leadership: None declared.

  4. Honorarium: None declared.


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Received: 2017-8-1
Accepted: 2018-1-22
Published Online: 2018-3-10
Published in Print: 2018-6-27

©2018 Walter de Gruyter GmbH, Berlin/Boston

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