Nondestructive characterization of and defect detection in timber and wood

In order to detect defects and to increase the lifetime of timber structures nondestructive methods are developed to monitor and assess their condition. Timber and wood can be characterized nondestructively and in many cases contactless with diverse methods. This paper gives a short overview on some nondestructive methods based on electromagnetic effects: microwave/radar, nuclear magnetic resonance and X-ray techniques. To monitor the stress condition of the joints in timber structures some other techniques like micromagnetic methods, acoustic resonance analysis and ultrasonic stress analysis are to be considered.