NDT technologies

Nanotechnology


EMAT - Electromagnetic Acoustic Transducer


Classic piezoceramic transducers have a limitation, that in order to transfer the ultrasonic energy, they need a contact with material under inspection. The contact can be provided by down-force, immersion, pressurized air.. Air-coupled method operate with air as a coupling medium and are adequate for composites. However, for metals, there is so great difference in acoustic impedance, that a signal, reflected from materials having a thickness greater than approx. several millimeters, is virtually inaccessible.

EMAT works only in conductive and ferromagnetic materials. compared to classic piezoelectric transducers, it enables series of applications, which are rather problematic. The EMAT principle consists in the Lotentz’s attractive force in magnetic field. The magnetic field orientation influents principally on generated ultrasonic wave type.

One specific advantage is that EMAT ElectroMagnetic Acoustic Transducer can work with high temperatures. It can be used when you need testing some materials directly in production line, and material is not still cold. Second very interesting advantage is that with EMAT you can generate lots of diferent waves.




* pressure transducers * ultrasonic thickness * telemetry system, devices * wall thickness * Eddy current * nondestructive testing * nondestructive inspection * Phased Array * EMAT * Nanotechnology *
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