Method and apparatus for non-destructively detecting hidden defects caused by bio-deterioration in living trees and round wood materials

摘要

A method and apparatus for detecting internal bio-deterioration in round wood used in various applications (e.g. utility poles, pier pilings, round wood beams, posts and poles in structures, and living trees). The method includes the steps of securing a pulsing transducer adjacent one point on the surface of the round wood and securing a receiving transducer substantially diametrically opposite to the pulsing transducer. The pulsing transducer transmits ultrasonic signals through the round wood, which propagate through possibly deteriorated areas within the round wood. The receiving transducer receives the propagating ultrasonic signals, and a plurality of acousto-ultrasonic parameters contained in the received ultrasonic signals are processed and analyzed. The processing step includes the step of storing the averaged signals, and processing the stored signals on a real time basis to determine the acousto-ultrasonic parameters in the time and frequency domains. Optionally, the averaged signals are windowed and then stored before the AU parameters are processed and analyzed. The processing step further includes the step of generating at least one fixed frequency to cause the pulsing transducer to resonate and to inject ultrasonic signals at fixed frequencies. The pulsing and receiving transducers are secured to the round wood with a variety of coupling apparatus.