The eddy current array technique (ECA) is a derivative of conventional eddy current testing and shares the same electromagnetic/inductive principles of eddy current.
The word “array” means that in comparison to a single coil sensor many adjoining eddy current coils are forming a coherent eddy current assembly. The decisive advantage of ECA probes is their larger coverage compared to single coil probes and thus a faster and more cost efficient scanning for the client.
The Eddy Current Array technique uses a multiplexer (MUX) to excite the single coil elements in a pre- defined scheme to leverage the probe’s width. Multiplexing also minimizes the interference between coils in close proximity (mutual inductance) and maximizes the resolution of the probe. Another advantage is the fact that each coil element is able both to transmit and/or receive eddy current signals (transmit/receive circuit). By this means different circuit modes can be realized which enables the technique to detect cracks or corrosion independently of its orientation in a single pass. The data-acquisition is linked to position-encoders. Thus high inspection reproducibility will be archived whereas the risk of untested areas will be minimized at the same time. An expressive full coverage 2D or 3D C-Scan report of all tested areas is another advantage of the ECA technique.
Advantages of ECA
- High inspection speed, rapid scanning
- High probe coverage, high test reliability
- Independent for defect orientation through intelligent multiplexing
- Probes can be adapted to complex geometries
- Inspection without physical movement possible
- Different inspections in one pass
- Expressive 2D and 3D C-Scans for full coverage reports
- High reproducibility
- Encoder-based data acquisition