OptiEMAT® testing devices

EMAT: What kind of technology is it?, Features and advantages

What is an EMAT?

A magnet, a wire, an air gap and a metallic surface.

  • is similar to an eddy current sensor
  • Sending an acoustic wave:
    A current pulse J induced through the conductor via the air gap G
    an eddy current I in the metal surface. This eddy current I
    generates with the static magnetic field a force F and thereby
    creates a directed sound wave in the metal surface.
  • Receiving an acoustic wave:
    An acoustic wave moves the surface in the magnetic field and
    generates an eddy current which induces a current J in the conductor
EMAT principle


Features and advantages of an EMAT inspection

EMAT combines all the advantages of the normal UT with other special advantages.

Ultrasound is generated in the component to be examined.

1. Dry inspection - no coupling medium

  • easy automation and integration into production
  • no coupling agent-induced errors
  • high inspection speeds (about 60 m / s)
  • can be used at high and low temperatures

2. Insensitive to the surface condition

  • Inspections on rough, dirty (greasy / wet), oxidized or uneven surfaces possible

3. Easy use of the sensors

  • no signal changes when replacing the sensors
  • small changes in the insonification angle do not affect the results (for example partial curvature)

4. Unique wave types

  • Generation of horizontally polarized shear waves
  • highly efficient, guided waves


EMAT testing devices



For integration into the production process

OptiEMAT adapter

OptiEMAT adapter

The EMAT adapter to extend the functionality of conventional ultrasonic testing devices

OptiEMAT mini

OptiEMAT mini

The testing device for use with smartphone, tablet or rugged PC

OptiEMAT mobil

OptiEMAT mobil

The portable EMAT testing device for mobile use on site