摘要：For many years work has been performed to obtain sufficiently accurate correlation between the results of ultrasonic tests and the results of strength tests for evaluation of the strength parameters of wood in a structure. It is also important to ensure the development of methods which will facilitate the work of construction mycologists; that is, non-invasive methods of determining the volume of missing materials caused by biological corrosion. The study presents the idea of the objective examination of the thickness of a corroded layer by measuring the velocity of ultrasonic pulse along the fibre length using for this spot heads with thin waveguides. Another testing method presented in the study is controlling the velocity of ultrasonic wave in the direction tangential to annual growth rings by conducting tests on the corner of the corroded beam.
