| 摘要 |
PURPOSE:To accurately detect presence of a damage on an object being measured and its degree, by dividing an AE signal into circuits of two system of different attenuation effects, and also by classifying and accumulating signals by attenuation ratios. CONSTITUTION:A signal, which is obtained from an AE sensor 6 attached onto an object being measured, is divided through a preamplifier 7 into high-pass filters 8a and 8b having different cut-off frequencies, and after passing through envelope detectors 9a and 9b, and peak-holding circuits 10a and 10b, ratios of respective peak values are measured in a ratio measuring circuit 11. The measuring output is put into a measuring circuit 18 through a modulation circuit 12, an FM transmitter 13, transmitting and receiving antennas 14 and 15, an FM receiver 16 and a demodulation circuit 17, classification is done by set widths, and counted by counting-and-memory circuits 19a-19n. Then, contents of the circuits 19a-19n are read out at a constant cycle and indicated on an indicating device 21. It is possible, by so doing, to accurately detect whether or not a damage is present on a member moving or even turning at a high speed. |
