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Eddy Current Testing for Defects: Maximizing Efficiency with Portable Instrumentation

Eddy current testing (ECT) detects flaws on a surface level and subsurface level, but it takes the right instruments to procure truly reliable data. Eddy current instruments can pinpoint underlying defects that would have gone unnoticed with other nondestructive testing (NDT) methods, including minuscule stress points that are harder to read. For the best results, NDT analysts can choose a handheld ECT instrument with a surface array addition or a portable surface array ECT instrument with tubing/surface array abilities.

The Convenience of Handheld ECT Instrumentation

The latest ECT instruments pair the power of advanced technologies with the convenience of portability—certain ones even come in handheld form. These instruments streamline inspection processes by eliminating the need for the electrical sources and post-inspection cleanup time necessitated by other more traditional NDT methods. Furthermore, instruments with impeccable signal acuity and a simple interface eliminate the need for lengthy setup times and cumbersome detection techniques.

The instrument scans through thicker sections of the tested asset, including hard-to-reach areas that other NDT techniques could not probe. An ECT device can detect the following above-surface and below-surface flaws or issues:

  • Corrosion
  • Cracking
  • Erosion
  • Conductivity and coating thickness measurement

Example: An NDT analyst must test for corrosion on a stainless steel pipe. However, the analyst received word that the item was already tested using other means. The analyst applies a handheld ECT device that was provided by a third-party NDT agency specializing in ECT training. Using a surface array probe with encoder, they pass through various parts of the pipe. The instrument picks up thin spots and corrosive sections not seen using the other inspection techniques and the encoder identifies the location of the defects. Thanks to the ECT solution, the analyst’s detection time was also cut in half. 

A core part of ECT functionality is impeccable signal-to-noise ratio (SNR), which should be sensitive enough to detect the smallest corrosion spots or thickness erosion points. Further, an ECT device with strong SNR can be provided by an NDT supplier that manufactures these devices and provides training on how to use them. 

The Benefits of Surface Array Speciality

There’s another portable ECT instrument that fosters the same level of quality detection when it comes to surface array inspections but is designed to handle more demanding environments. Though not as ergonomic as the handheld version, this type of ECT instrumentation features built-in surface array capabilities that outline the full profile of a defect in impressive detail. Regardless of the ECT instrument chosen, surface array probing can also reduce inspection times by up to 95 percent when compared to pencil probing and can detect anomalies through paint, unlike magnetic particle testing (MPT) or liquid penetrant testing (LPT). Moreover, surface array ECT eliminates the following hassles commonly associated with other NDT methods:

  • Use of chemicals during the testing stage
  • Surface preparation
  • Conduciveness

Certain NDT methods, such as MPT, are not conducive to non-ferromagnetic materials. Surface array, in contrast, is conducive to both ferromagnetic and non-ferromagnetic materials.

Example: An NDT inspector must test a raised welded item for stress points. Using the surface array feature, they attach a surface array weld probe. The probe conforms to the curvature of the weld. The analyst finds a crack, and the surface array feature allows them to measure the size of the minute defect. Now, the analyst can determine how dangerous the stress point might become.

Ideally, the instrument that powers the surface array probe should be portable and battery-operated. It should also be able to detect problematic cracking that’s easy to miss, such as:

  • Off-axis cracking
  • Transverse cracking
  • Longitudinal cracking

Surface array can detect these defects for surface and subsurface areas. Such minor flaws could pose long-term damage in the long run if left unattended. The in-depth focus method behind surface array relies on not only high-quality SNR but also advanced sensor technology.

Testing for Defects with Eddy Current Technology

Top-quality ECT equipment can help owners and managers spot hidden flaws that could cripple operations in the future. Investing in ECT also helps managers streamline maintenance budgets by commencing the necessary asset repairs at earlier dates. Companies can foster operational efficiency while enhancing workplace safety in the process.

ECT is a crucial NDT service that can secure public safety, especially in industries such as oil and gas, manufacturing, and aerospace. To get the best results, users should use a handheld ECT instrument or a portable instrument with tubing and surface array features. With eddy current testing, defects can be easy to locate—but only when analysts are equipped with reliable instrumentation provided by a trusted NDT manufacturer.

Zetec provides some of the best ECT and UT equipment on the market. For more information, contact Zetec today to get a custom ECT plan and the latest ECT equipment and training for your NDT analysts.