# Eddy Current Testing for Education

In the ET module, two types of computation are available: beam computation and inspection simulation.

## Field Computation

The capabilities of the field computation include:

• Planar (potentially multilayer) and Cylindrical component geometries
• Ferromagnetic or non-ferromagnetic materials
• Surface coil (air core or cylindrical ferrite core), bobbin coil configuration
• Variable operational frequency
• Computes electromagnetic fields, impedance diagram and lift-off signal

### Examples of simulations

The ET field computation module of CIVA Education can help you make visible what is a bit hidden and looks complex in this electromagnetic technique:

• Illustrate the Eddy Current penetration depth and observe the impact of the frequency, the material but also the sensor size on the actual penetration.

• Visualize the action zone of an ET sensor.
• Observe Eddy Current distribution in a tube or a solid bar.

• Understand and interpret Impedance diagram.

• See the influence of a ferrite core on the field induced by an ET sensor.
• Explain the lift-off signal and its potential consequence on calibration procedure.

• And many other ideas...

## Inspection simulation

The features available in the ET inspection simulation module are:

• Planar and Cylindrical component geometries
• Conductive non-ferromagnetic materials
• Surface coil (air core or cylindrical ferrite core), bobbin coil configuration
• Simulation of cylindrical hole in tubes or rectangular notch in planar component
• Variable operational frequency
• Absolute or Differential mode

### Examples of simulations

The ET inspection simulation module of CIVA Education can reproduce typical Eddy Current signals and help you in the following context:

• Explain the main acquisition modes: separated or common functions, absolute or differential measurement.
• Simulate classical tube inspection setup and explain the use of the phase angle for the defect characterization.
• Illustrate signals obtained at the quadrature frequency for different defect depths in tube inspection.

• Highlight the influence of the filling rate on the inspection sensitivity.

• Show the impact of the inspection speed on the signal resolution for a given operational frequency.
• Illustrate the impact of the sensor size for a given flaw on the obtained response.
• See what happens if you apply or not the “law of similarity” on a defect signal.
• Evaluate the impact of the material conductivity on the signal obtained for a similar defect.

• Visualize the phase separation of lift-off and defect signal depending on the sensor and the operating frequency.
• Etc.