Multiple-channel trigger circuit for noise discrimination in ultrasonic acoustic emission studies.
Denver, CO: U.S. Department of the Interior, Bureau of Mines, IC 9425, 1995 Jan; :1-18
Transient electrical noise events pose serious problems for data aquisition systems monitoring acoustic emissions in laboratory and field environments. The U.S. Bureau of Mines, as part of a study aimed at using ultrasonic acoustic emissions to warn of impending structural failure and stress transfers in underground coal mines, has designed and constructed a trigger discriminator circuit for use in ultrasonic acoustic emission (UAE) studies. Desgined for use with signals in the frequency range of 50 kHz to 400 kHz, the instrument examines incoming signals for frequency content, amplitude, simultaneity, threshold crossings, and number of channels above threshold. The system was designed for four input channels, but may be expanded to more channels with minimal design changes.
Coal-mining; Wave-propagation; Noise-threshold; Amplitude; Channels; Acoustic-detection; Trigger-circuits; Electromagnetic-noise; Discrimination; Acoustic-signals; Ultrasonic-frequencies
NTIS Accession No.
Denver, CO: U.S. Department of the Interior, Bureau of Mines, IC 9425