Understanding Acoustic Emission Testing- Reading 1 Part B-A

2. Preamplifier: Because of the low voltage output (≤100μV) , the leads from
the transducer to the preamplifier must be as short as possible; often, the
preamplifier is integrated within the transducer itself. Typically, the gain in the
preamplifier is in the range 40 to 60 dB (x100, x1000). (Note: The decibel
scale measures only relative amplitudes. Using this scale:
where V is the output amplitude and Vi is the input amplitude. That is, a gain
of 40 dB will increase the input amplitude by a factor of 100; a gain of 60 dB
will increase the input amplitude by a factor of 1000, and so on.)
Charlie Chong/ Fion Zhang