| 摘要 |
PURPOSE:To collect abnormal sounds generated in the range different from the axial direction of the sensor in such a manner that different components from acoustic emission(AE) itself generated in the ground are not detected, by setting a microphone in a container filled with a fluid. CONSTITUTION:A fluid 2 with a high sound-propagation efficiency such as water or low viscosity oil, etc., is filled in a container 1 composed of metal, resin, rubber, etc. And a microphone 3 of a condenser type, a piezo-electric type, an electromagnet type, etc.,having a structure in which an oscillating plate 3a and the liquid 2 contact directly each other, is set in the container. And hence, AE generated in the surrounding ground 5 reaches the container 1 wall and propagates through the liquid 2 to actuate the oscillating plate 3a of the microphone 3 and then it is converted to electric currents. In this way, AE in the ground can be detected without loss. |
