A Modular System for Continuous Recording of Acoustic Emission for Laboratory Studies of Rock Destruction Processes

Abstract

The MSR-AE-21 high-speed multichannel system for recording AE signals was developed, based on modern E20-10 four-channel 14-bit ADCs, produced by the Russian company LCard. The system is designed for continuous and synchronous recording of the acoustic emission (AE) stream from 21 piezoelectric sensors and is used as part of a laboratory hardware–software system for testing rocks under uniaxial and triaxial strain conditions. A digitization frequency of up to 7.5 MHz per channel makes it possible to analyze in detail AE signals with a frequency of up to 750 kHz. The 40 dB preamplifier block has a bandwidth from 1.5 to 750 kHz. Continuous recording over all channels during the entire test time makes it possible at the end of recording to search for and identify acoustic events in a wide dynamic range of amplitudes and energies with minimal loss/omission of individual AE events. The use of fast information processing algorithms makes it possible to recognize events in real time, detecting and discarding intervals with no signals and thereby reducing the total amount of information recorded in the database.