Home » Technologies » Electro-Magnetic Acoustic Transducer (EMAT)

Electro-Magnetic Acoustic Transducer (EMAT)

With EMAT (Electro Magnetic Acoustic Transducer) technology, we generate and detect ultrasounds with an electromagnetic process, instead of a piezoelectric one just like in the case of conventional and phased array ultrasounds.

It is the sure technique when ultrasounds nor piezoelectric transducers can not be used, for different reasons: be it a very high temperature, couplant presence, or the material type.

EMAT Technology
EMAT technology does not require couplant, which is a major advantage. Indeed, when there is a high temperature, piezoelectric transducers can fail, and couplant can dry instantaneously because of the too high temperature. EMAT are advantageous also to inspect a highly corroded surface. For example, in petrochemical industry, pipe walls are sometimes so flaky, their surface is such in a bad shape that, even with couplant, transducer can not have a frank contact. EMAT technique is at that point very useful, because it allows not being in direct contact with surface.

An EMAT transducer is composed of a magnet and an electrical coil, and depends on the electromagnetic interaction in order to generate elastic waves. With the Lorentz Force and magnetostriction, the EMAT transducer and the metal testing surface interact and generate a sound wave into the material. The material to be inspected is, in fact, its own transducer. Since it is not possible to use coupling between the transducer and material, EMAT technology is particularly indicated for automatized inspections in difficult environments.