Acoustic emission testing – an overview

Acoustic emission testing is the Non-destructive Testing (NDT) technique that is based on the generation of waves that are produced by the sudden distribution of stress in an object. It involves the method of using the change in pressure, load, the temperature in an object due to the external stimulant. The external stimulant triggers the release of energy or the stress waves from the object to the surface. It is recorded by the sensors.

Earthquakes or rock bursting are some of the natural sources of acoustic emission The detection and analysis of Acoustic emission give the essential information on the origin and importance of discontinuities in a material such as a metal. 

Acoustic emission testing works by mounting small sensors in a component that should be tested. The sensor converts the stress waves into an electrical signal that is sent to the acquisition PC. The object when extorted with an external stimulus such as high loads, pressure or temperature will emit the waves that are captured by the sensor. Greater the stress, higher he releases of energy. The rate of acoustic emission, the intensity of acoustic emission, loudness – are all monitored and used in assessing the component.

Acoustic emission technique involves monitoring the component for defects while in operation with least disruption, unlike the destructive testing technique. Multiple sensors are used for locating the acoustic emission sources and the damage. This signal analysis can be used to determine the presence of different source in a component. 

Acoustic emission testing methods

Acoustic emission testing can be completed in a laboratory, or at sites. It can be done within a relatively short durations (few hours) or longer durations, (a few months) depending upon the need of the test. Wireless data relay methods are also used for the analysis of the data remotely. 

The two methods of acoustic emission testing methods are – 

Transient method

The transient method is used to check the structural defects such as the crack by capturing Acoustic emission that exceeds a threshold level. It is used to extract features of a component such as peak amplitude, signal energy, and duration of the burst. All of these features are used to assess the condition of the component under test. 

Continuous method

The continuous method captures all Acoustic emission that is emitted within a fixed period to calculate the features such as average signal level and root-mean-squared (RMS) values. This method is for testing gearboxes or detecting leaks in a system. This method of AET deals with dynamic processes in material and are useful method as the active features are highlighted during the examination.

At Coltraco Ultrasonics, our accosting emission testing products are carefully hand-built and undergo rigorous quality testing to ensure that they meet the high standards that are expected by our customers. We assure you to provide them with long term reliability on all the products purchased from us. Coltraco acoustic-based monitoring tool is the first of its type in the world, the pocket-size Portamonitor. Contact us to know more about the details of our products.