| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pipeline clogging object diagnostic method capable of accurately diagnosing accumulation of a clogging object in a pipeline. <P>SOLUTION: An acceleration sensor 2 is attached on an external surface of a drain pipeline 7. The acceleration sensor 2 is connected to a signal processor 3 via a FFT analyser 3. The drain pipeline 7 is vibrated by hammering the external surface of the drain pipeline 7 with a load sensor built-in impact hammer 6. This vibration is measured by the acceleration sensor 2 and inputted into the FFT analyser 3 as a vibration signal. A striking force to the drain pipeline 7 at this time is measured by the load sensor and inputted into the FFT analyser 3. The FFT analyser 3 determines the amplitude change of a transfer function with respect to a frequency based on the vibration signal and the striking force. The signal processor calculates the mode attenuation ratio of a natural vibration mode based on the transfer function. Accumulation of a clogging object in the drain pipeline 7 is diagnosed based on this mode attenuation ratio. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
