Near Field Array Testing (NFA)

Near Field Array Testing (NFA): Advanced Inspection for Ferromagnetic Tubes

Near Field Array (NFA) is a nondestructive electromagnetic inspection method designed for ferromagnetic and fin-fan type tubes. Using array technology, NFA efficiently detects internal surface discontinuities, corrosion, and pitting with high resolution.


How It Works

Array Coil Configuration

Multiple coils are arranged in the probe to cover the tube surface circumferentially.

Flaw Detection

Defects like pitting or internal corrosion disturb the magnetic field.

Signal Processing

The system analyzes coil signals to locate, size, and map discontinuities accurately.


Key Advantages of NFA

  • High Resolution: Detects small and localized defects precisely.

  • Efficient Coverage: Array design allows faster inspection of large tube bundles.

  • Reliable Performance: Effective on fin-fan and carbon steel tubes.


Ideal Applications

  • Fin-fan heat exchanger tubes

  • Carbon steel ferromagnetic tubing

  • Boilers and feedwater heaters

  • Industrial systems requiring detailed defect mapping