Material Properties

Conductivity and Resistivity

Conductivity is a key parameter for EMAT and Eddy Current inspections since they both require electromagnetic induction to work. In case of EMAT, higher conductivity generates stronger eddy currents which will typically result in stronger ultrasound generation. For EC, higher conductivity values will typically result in greater sensitivity to surface defects and less penetration in the material.

Both EMAT and EC will also be affected by the magnetic permeability and excitation frequency. Contact us for additional information.

Conductivity Table

Magnetic Permeability

Magnetic Permeability determines the degree of magnetization that a material can achieve in response to an applied magnetic field. For sound generation with EMAT, magnetic permeability can enhance the signal through the magnetostrictive effect. For EC, higher magnetic permeability will reduce the penetration depth of eddy currents in the material.

Permeability Table

Ultrasound, Velocity, Density and Impedance

The velocity of ultrasound, density of material, and impedance (resistance to acoustic flow) are all relevant properties for any UT technique, including EMAT and Dry-Coupled UT (DCUT).

Acoustic Properties