 |
ULTRAKRAFT JSC designs and manufactures automated ultrasonic testing systems based on electromagnetic acoustic (EMA) transduction. |
How EMA Transduction Works
An inductor carrying high-frequency current generates an electromagnetic field that excites elastic vibrations, i.e. ultrasound, directly in the surface layer of the metal. The ultrasonic frequency is equal to the field frequency or a multiple of it.
Ultrasound reception relies on the inverse effect: vibrations of the metal induce a current in the transducer coil.
ADVANTAGES OF EMAT TECHNOLOGY:
No couplant is required, so EMAT testing can perform tasks that are beyond the reach of the piezoelectric method:
- reliable and accurate testing of objects with contaminated surfaces;
- testing of objects moving at high speed;
- testing of objects with extreme curvature;
- testing at low and extremely low temperatures;
- testing of very hot objects, up to 1200 °C.