allow to measure environmental condition like load, temperature etc. ASIP-2 signal processor contains two independent channels for AE input signals. This module also ensure power supply for preamplifier. Some technical data of AMSY-6 system is shown in Table 1. Tests were performed using sensor type VS900-M which is a passive piezoelectric AEsensor with a broad frequency response. Table 1. General technical data of AMSY-6 system (www.vallen.de) ASIP-2/A (Advanced version) Name Description Preamplifier power supply 28 V DC ADC (Analog-Digital Converter) 40 MHz at 16 bit per channel System noise 1.5 µVRMS (95 – 300 kHz filter) Filters Band-pass filter with low-pass and high-pass filter 8th order Butterworth each Memory 512 MB Sampling rate 333 kHz – 40 MHz (for channel) Preamplifier AEP5 (H) Gain 34 dB or 40 dB (selectable) Bandwidth (-3 dB) 20 kHz to 2.4 MHz (10 VPP) Input impedance 50 MΩ Sensor VS900-M Frequency range 100 – 900 kHz Operation temperature -50 to +100 ºC Weight 20 g Figure 3 shows a typical set of outputs from acoustic emission (AE) / seismoacoustic monitoring performed during controlled loading of a rock specimen. As the applied load or stress increases, the system records individual AE hits/events (green markers) and tracks how their activity evolves with time and stress. From these data, key quantities are determined, including the cumulative AE response (green bars/curves) and the onset of accelerated AE activity, which is used to identify the Kaiser point (σK)—i.e., the stress level at which the specimen begins to emit AE in a manner consistent with stressmemory. The central event table lists parameters for each detected hit (time, channel/sensor, amplitude, rise time, duration, counts, energy/RMS, frequency-related descriptors, and quality flags). The lower panels show the raw waveform of a selected hit and its frequency spectrum (FFT).
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