FACILITY FOR ACOUSTIC-EMISSION INSPECTION OF BUILDING MATERIALS

摘要

FIELD: nondestructive testing of building materials based on analysis of acoustic emission signals. SUBSTANCE: facility for acoustic-emission inspection of building materials has two identical resonance primary piezoelectric transmitters based on ceramic separated in space of tested object and two electroacoustic paths. Each path incorporates preamplifier with gain factor 40 dB, band-pass filter, amplifier and detector. Outputs of detectors of each electroacoustic path are connected to line inputs of 16-digit analog-to-digital converter operating on frequency 44.1 kHz and signals from analog-to-digital converter are assumed to be as carrying information on acoustic event only when difference in their levels in absolute value would not exceed certain threshold level specified in advance. Signal are discriminated by programmed computer. EFFECT: raised noise immunity of inspection of building materials in signal frequency band of 20.0-200.0 kHz.