OmniScan MX Eddy Current Array Flaw Detector

Eddy current testing (ECT) technology works on the principle of magnetic coupling of a probe sensor (coil) close to a test specimen (conductive material, ferromagnetic or non-ferromagnetic), generating eddy currents inside the test specimen, and displaying signals on the instrument’s impedance plane. With eddy current technology, you can detect defects through thin coatings (such as paint), as long as the distance from the probe to the metal is kept reasonably low—typically in the order of 0.5 mm to 2.0 mm.

As eddy current array and ECT technology share the same basic principles (and physics), it can also perform inspections through paint while offering all advantages of ECA, including large coverage, fast scanning, high probability of detection and color imaging.

Probes used to perform eddy current inspections are made with a copper wire wound to form a coil. The coil shape can vary to better suit specific applications.

1. The alternating current flowing through the coil at a chosen frequency generates a magnetic field around the coil.
2. When the coil is placed close to an electrically conductive material, an eddy current is induced in the material.
3. If a flaw in the conductive material disturbs the eddy current circulation, the magnetic coupling with the probe is changed and a defect signal can be read by measuring the coil impedance variation.

Calibration of ECA is done in a nearly identical fashion as conventional ECT. The principles of lift-off, gain and null adjustments are maintained so calibration is no more complex or time-consuming than usual.

Generate live lift-Off signals with ECA probe – just like with a conventional ECT probe.

Adjust the phase angle in real time with the OmniScan knob. Gain, Vertical Gain and Null Point (H/V) can also be adjusted the same way.

Even after an in-field inspection has been completed, the OmniScan^® MX ECA continues to provide value thanks to integrated data-storage, analysis, and reporting functionalities. With the OmniScan MX ECA you can review individual indications and apply corrections as needed. The new MXE 3.0 ECA software features newly redesigned, intuitive data cursors that can be operated directly from the instrument (on-site) or with a mouse connected by USB (office use).

New MXE 3.0 selection cursors are very intuitive and allow to quickly select any indication.

Corrections can be easily done on recorded data. Above example shows gain (contrast) adjustment.

The OmniScan^® MX ECA not only displays ECA signals in a conventional ECT impedance plane view but also offers several other views and layouts where the user will begin to recognize the true power of encoded ECA technology. These displays can be made part of the calibration workflow and can make eddy current testing highly visual and even go/no-go, based on user defined acceptance criteria.

Thanks to its intuitive interface design, the OmniScan MX ECA is quick and easy to configure and operate. It is as simple as one, two, three.

1. Adjust the usual ECT controls in real time using the live impedance plane.

2. Activate the encoder and C-scan display.

3 Fine-tune the settings and get ready to perform the inspection.

Contrast adjustment using the gain in full C-scan display.

As with conventional eddy current technology, flaw severity is closely correlated to the return EC signal amplitude in most surface or near-surface applications. By using an amplitude-based color code, and plotting each channel’s return signal with encoded-position information, the resulting C-scan display is highly visual and intuitive. These scans can be saved to the removable CF card or generated into a report onboard the OmniScan® MX.

A reference standard with known depth defects is necessary to calibrate the sensitivity and contrast of ECA.

Image of a calibrated ECA scan showing different colors for each defect depth range.

Actual aircraft skin showing corrosion indications. The colors indicate the depth of the defects.

Simultaneous connection of ECA and ECT probes provides the best tool for the job without the need to stop and reconfigure your hardware setup

ECA interface (blue) is as easy to use as the ECT mode or a Nortec 500.

Press and hold menu key…

ECT interface (green) includes several features for procedure compatibility, such as adjustable null position.

The Doubler Edge Skin Crack Inspection solution utilizes the latest ECA technologies for subsurface detection. The C-scan allows for higher probability of detection and better reproducibility. This solution is a major step forward in terms of reduced inspection time.

The Subsurface Crack ECA inspection solution is capable of scanning through the first aircraft layer (skin) to detect cracking present on the 2nd layer, without the need for paint removal. This solution is available in two ECA probe versions (commercial and military aircrafts), both covering at least 64 mm in a single pass.