Tubing Probes

Array Probes

Eddyfi has taken near-field testing (NFT) to a new level, supercharging it with an array of coils, giving birth to near-field array (NFA) technology. It is designed to efficiently and reliably inspect aluminum-finned tubes and ferromagnetic heat exchangers.

Aluminum-finned carbon steel tubes are the most challenging tubular component to inspect. The external aluminum fins on these tubes greatly influence the quality of inspection signals. Our NFA probes can easily detect common defects found in fin-fan air cooler tubes or ferromagnetic heat exchangers. They include: inner-diameter (ID) pitting, internal cracking at the tubesheets, internal erosion, and wall loss.

Benefit 1 — Array Performance and Quality

Eddyfi NFA probes can have up to 30 coils, optimized for performance. They are multiplexed, which yields high-quality signals, enables C-scan imaging at a scan speed of 305 mm/s (12 in/s) in tubes ranging from 19.05 mm to 38.10 mm (0.75–1.5 in).

Benefit 2 — Sizing Capability

NFA gives our probes the high resolution necessary to reliably detect and size small volumetric defects (approx. 3 mm or 1/8 in) in a single pass.

Benefit 3 — Ease of Use

Unlike other inspection techniques, our NFA probes are easy to use. Because they don’t incorporate any magnets, they are easy to push and pull through tubes, and are not as sensitive to pull speed as MFL probes. NFA probes also do not require water or complex tools, making them much easier to use than IRIS.

Benefit 4 — Intuitive Imaging

With Eddyfi’s Magnifi, you can display NFA probe data as 2D/3D C-scans, which are intuitive and rich in information. This enables the discrimination and sizing of defects.

Benefit 5 — Durability

Our NFA probes are equipped with hardened-steel, wear-resistant guides to maintain a constant liftoff and yield more reliable results. These guides are replaceable, so when they do wear down, it’s easy to keep using the same probe.

They are also equipped with a high-end, kink-resistant poly, enhancing probe usability and life.

Use the Part Number Finder to see what Eddyfi probes are available or use the Tubing Probe Creator to determine what probes are best for your particular application.


Fin-Fan Air-Cooled Heat Exchangers: Inspection Technique Comparison for Optimal ResultsFin-Fan Air-Cooled Heat Exchangers: Inspection Technique Comparison for Optimal Results

To be able to make better inspection technology choices before inspecting fin-fan air coolers:

  • Learn about conventional inspection techniques and how they compare (NFT, MFL, PSEC)
  • Learn about more advanced inspection techniques and how they compare (NFA, IRIS)



Coil technologies

  • Absolute
  • Array (pitting, circumferential, and axial)

Maximum test speed

305 mm/s (12 in/s)

Minimum detectable defect size

3 mm (1/8 in)

Target materials

Ferrous. Carbon steel and low-carbon steel alloys


9 mm (0.375 in) premium, non-kink nylon


160-pin array connector

Calibration standard

Modified NFT calibration standard