| 摘要 |
PURPOSE:To measure the age of a wood with accuracy by installing a plurality of electroacoustic tranducers so as to locate them at positions symmetric with respect to the center of the wood and to make them contact with its internal structure. CONSTITUTION:Transducers 2a and 2b are installed at positions that are symmetrical with respect to the center 6 of a wood 5. Next, the output of a signal generating device 1 is sent to the transducer 2a through a transmission wire 4b. The transducer 2a converts the output signals into elastic waves and radiates them into the wood 5. A part of the elastic waves pass annual rings 8a, 8b,... to reach the transducer 2b. On the other hand elastic waves 10a and 10b reflected from annual rings 8a, 8b,... reach the transducer 2a. The transducers 2a and 2b convert thereby elastic waves into electric signals and sent them to a processing device 3 to measure accurately the age of a wood. |
