| 摘要 |
A method and apparatus is disclosed for the non-destructive testing of the quality of a fibrous material, such as wood (9), by the use of sound or shock waves input into the material. The shock wave is generated by striking an input means (20) against the side of the tree with a hammer (4). A first transducer (14) in communication with the input means signals when the input means is struck. The apparatus also includes a second transducer (16) in communication with a spike (22) that penetrates into the tree at a fixed distance (A) from where the input means engages the tree. The shock wave travels longitudinally along the tree, and when the shock wave reaches the spike the second transducer signals the event. The time taken for the wave to travel from the input means to the spike is measured from the time between the two transducer signals, and the velocity of the wave is calculated. The modulus of elasticity (MOE) of the wood is then determined and, thus, the quality of wood that the tree will provide is measured. |
