Principles of Operation
Electro-Magnetic Imaging uses Electro-Magnetic Field Imaging (EMFI) to display surface breaking defects in a three dimensional image.
It creates a large hemi elliptical toroidal field below the Sensor. The field shape is measured in the X, Y and Z planes by specially shaped antenna coils.
Material permeability, conductivity, shape and distance from the surface to the sensor all affect the shape of the field.
As the Sensor passes over a surface breaking defect, such as a crack, SCC, or corrosion, the shape of the field is deformed.
The degree and location of the field shift is measured and the translated into crack location, direction and depth. EMI has the ability to detect surface breaking cracks in both ferrous and non ferrous materials.
The material is not left with a residual magnetic field and therefore does not require degaussing prior to return to service.
Accurate Data Acquisition
Stress Crack Corrosion
C-Scan of the SCC Plate