| 摘要 |
<p>Monitor for detecting abnormalities and thus determining the operating condition thereof by continuously computing the power spectrum of the monitored sound and has two modes of operation: learn and operate. The monitor is placed in the learn mode during a time when the machine or process to be monitored is known to be operating normally. During the learn mode, the maximum and minimum acoustic power output from each of a plurality of digital bandpass filters is continuously maintained and updated in data memory as the acoustic signature of the machine or process being monitored. During the operate mode, the monitor continuously compares the real-time filter outputs with the acoustic signature stored during the learn mode and activates a panel lamp and relay if the output of any of the bandpass filters deviates from the upper or lower decibel limits of the acoustic signature by more than the setting of the corresponding front panel sensitivity selector switch. Two alarm levels are provided by the monitor: warning, to indicate a developing fault, and danger, to indicate a situation requiring immediate corrective action.</p> |
