Understanding Acoustic Emission Testing- Reading 1 Part B-A

16.4 Evaluation of Acoustic Emission Signals
A typical acoustic emission signal from concrete is shown in Figure 16.2.12
However, when such acoustic events are examined in much greater detail, as
shown in Figure 16.3, the complexity of the signal becomes even more
apparent; the scatter in noise, shown in Figure 16.3, makes it difficult to
determine exactly the time of arrival of the signal; this means that very
sophisticated equipment must be used to get the most information out of the
acoustic emission signals. In addition, to obtain reasonable sensitivity, the
acoustic emission signals must be amplified. In concrete, typically, system
gains in the range of 80 to 100 decibels (dB) are used.
Comments:
20log (I/I o ) = 80, (I/I o ) = 10000
20log(I/I o ) = 100, (I/Io) = 100000
Charlie Chong/ Fion Zhang