EMAT Applications

Normal (zero degree) Beam

Characteristics

  • Direction of Propagation: Perpendicular to the entry wall.
  • Sensor Configuration: Pulse-echo (transmitter = receiver) or pitch-catch (transmitter ≠ receiver).
  • Wave modes: Shear Horizontal and Longitudinal waves in frequencies ranging from 500KHz to 10MHz. Whereas EMAT can generate both Shear and Longitudinal waves at 0 degrees, Shear (Horizontal) waves are easier to generate.
  • Materials Inspected: Ferromagnetic and non-ferromagnetic metals.

Applications

  • Thickness Measurement
  • Corrosion and erosion measurement.
  • Flaw detection, such as, inclusions, de-laminations and disbond.
  • Acoustic velocity measurement.
  • Rolling direction recognition.
  • Anisotropy and stress measurement.
  • Nodularity measurement.
  • Bolt-Load measurement.

EMAT Uniqueness

  • Dry and non-contact. Practical working distance from the coil to the part (lift-off) is usually between 0-3mm. Greater lift-off can be achieved (up to 10mm in laboratory settings), depending on material, equipment and type of inspection. Ideal for automated and hot environments.
  • Not affected by surface conditions (coatings, oil, oxide).
  • Maintain