Understanding Acoustic Emission Testing- Reading 1 Part B-A

Sensors / Source Location Identification
The most commonly used sensors are resonance type piezoelectric
transducers with proper couplants. In some applications where sensors
cannot be fixed directly, waveguides are used. Sensors are calibrated for
frequency response and sensitivity before any application. The AE technique
captures the parameters and correlates with the defect formation and failures.
When more than one sensors is used,
• AE source can be located based by measuring the signal’s arrival time to
each sensor. By comparing the signal’s arrival time at different sensors,
the source location can be calculated through triangulation 三 角 测 量 and
other methods.
• AE sources are usually classified based on activity 活 动 力 and intensity 强
度 . A source is considered to be active if its event count continues to
increase with stimulus.
• A source is considered to be critically active if the rate of change of its
count or emission rate consistently increases with increasing stimulation
变 化 率 随 着 刺 激 增 加 不 断 提 高 .
Charlie Chong/ Fion Zhang