US (International)
Group: Inspection
Eddy Current testing is based on electromagnetic principle as the basis for conducting material inspections. When an alternating current is applied to a probe, a magnetic field produces. When a secondary conductor is approached into the magnetic field of probe, an induced current flow through the conductor. This induced current is Eddy current.
These eddy currents generate their own “secondary” magnetic field that opposes the coil’s primary magnetic field, causing a change in the impedance of probe as a presence of the conductor.
There are two major inspections which the traditional eddy current method can use. These are:

1. crack detection: the presence of crack or any defect cause a disruption in the circular flow pattern of eddy currents and this change can affect the impedance of the coil

2. Conductivity measurement: Eddy current inspection method is highly sensitive to any change in the conductivity and magnetic permeability of materials. As a result, Eddy current method is an excellent tool for material soring & material identification.

Multi-frequency Eddy Current Inspection method is to derive a probe at more than two frequencies. This type of inspection helps us to gather more information about the object being inspected. The comparison of a discontinuity at different frequencies, or even mixing of frequencies to eliminate or reduce noise, improve detection, interpretation and sizing capabilities. 

It is essentially important to calibrate the eddy current instrument based on reference standard manufactured from the same or very similar material as the test specimen. 

The advantages of eddy current method are listed as follows:
- sensitive to small cracks, subsurface defects
- immediate results
- portable equipment
- minimum preparation
- non-contactable
- can be used to inspect complex shape and size of different materials
But the limitation is only conductive material can be inspected. 

Moreover, EddyWise can inspection for you. To know more about our service, please download the catalog mentioned as follows
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