| 摘要 |
<p>The panel is set in vibration by an excitor (22) and changes in the pattern of vibration due to the loading or damping of the panel by an attached device are detected. The input from piezoelectric detectors is passed by amplifier (12) and analog-to-digital converter (13) to a microprocessor (14). Under control of programs held by EPROM (16) the inputs from successive test cycles are analyzed and compared to determine whether a significant change in the condition of the panel has recurred, in which case an alrm is given by an indicator (25).</p> |
