NDT Acoustic Emission Testing 2

Question 1

What is the primary function of a preamplifier in an acoustic emission testing system?

Accepted Answer

To amplify the small AE sensor signal before transmission to the main amplifier

Answer

The preamplifier amplifies the low-voltage AE signal (typically microvolts to millivolts) close to the sensor to improve the signal-to-noise ratio before the signal travels through cables to the main system.

Question 2

The Hit Definition Time (HDT) parameter in AE data acquisition is used to:

Accepted Answer

Determine when an AE hit has ended by timing from the last threshold crossing

Answer

HDT (also called hit lockout time) defines how long after the last threshold crossing the system waits before declaring a hit complete, preventing a single emission from being split into multiple hits.

Question 3

For linear source location in acoustic emission testing, what is the minimum number of sensors required?

Accepted Answer

Two

Answer

Linear (1D) source location requires at least two sensors; the source position along a line is calculated from the difference in arrival times (delta-T) between the two sensors.

Question 4

Which of the following best describes signal attenuation in acoustic emission testing?

Accepted Answer

The loss of AE signal amplitude as the wave propagates through the material

Answer

Attenuation in AE testing refers to the reduction of signal amplitude with increasing distance from the source due to geometric spreading, material damping, and scattering.

Question 5

The detection threshold in an AE system is set to:

Accepted Answer

Exclude background electromagnetic noise while capturing true AE signals

Answer

The detection threshold is a voltage level set above the background noise floor so that only genuine AE signals exceeding it are recorded, preventing false hits from electrical or mechanical noise.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Acoustic Emission Testing 2