A. E. データ集録・処理システム
大理石の破壊実験への適用
1979 年 32 巻 3 号 p. 233-241
詳細
1979 年 32 巻 3 号 p. 233-241
A recording and reproducing system for acoustic emissions and its application to fracture experiment using marble sample are reported.
This system consists of preamplifiers, high speed A/D converters, a digital memory unit, D/A converters, a magnetic tape (MT) unit, and a minicomputer. A. E. signals are digitized and stored in the memory. High frequency A. E. signals are converted to lower frequency ones using the memory unit. Then, the signals are transferred to a MT. The same process is repeated to send data in a MT to a computer.
Characteristics of this system are as follows; (1) the dynamic range is 40 dB, (2) the high frequency limit of pass band is 2MHz, (3) the maximum sampling rate is 50 nsec/word, (4) the maximum emission rate in which A. E. s are correctly recorded is 200 events/sec. If the emission rate is less than 200 events/sec, A. E. activity recorded on a MT has the same statistical characteristic as that of original signals in spite of the conversion of frequency and data length.
