| 摘要 |
A non-intrusive vibration monitoring apparatus and method uses ultrasonic transducer means (46, 50) to transmit and receive ultrasonic pulses to and from a vibrating internal part (22, 66) of a body (20, 72). A record of pulse emission and reception times is made by recording means (16, 18), and the recorded data is digitally filtered to provide a visual display (62) from which quantitative measurements may be made. Commercial ultrasonic instruments may be used together with digital signal filtering and analysis techniques to enable quantitative detection of vibrations as small as 1 x 10<-><3>m (0.04 inch) peak-to-peak. The system may be used for in-service vibration monitoring of internal components of check valves, pumps, nuclear reactors, steam generators and heat exchangers, especially when the vibration frequency is too low for quantitative analysis by accelerometers and when the strain induced is too low for strain gauge analysis. <IMAGE>
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