The issue of the thesis fall under the department of non destructive testing of wood. The thesis description is an experiment, which includes the measurement by application of a new semi destructive device on wooden beams commonly used in historical constructions in the Czech Republic. This measurement was monitored by DIC technology at the same time. The part of the results of work is also the treatise about the influence of different factors like the wood density, moisture content and others. This final thesis also discusses about the accuracy and appropriateness the measurement by a new diagnostic device for in-situ determination of strength and modulus of deformability in compression of wood parallel to fibers.