Electromagnetic Acoustic Resonance

At a Glance

All Resonic NDT instruments utilize a specialized test technology called electro magnetic acoustic resonance (EMAR) for a variety of quality testing applications on manufactured metal products.

EMAR is a unique approach to manufacturing quality testing using electromagnetic-acoustic transducer (EMAT) sensors with resonance spectroscopy. The technique is founded upon traditional RUS/RAS test methods but is different in the way that it uses a contactless sensor design with a faster and more selective analysis of natural resonant modes for detection of defects. ARIS products are intended for testing of new, manufactured metal products.

Resonic's Acoustic Resonance Inspection Systems are the only commercially available EMAR products in the world. Our products are built upon years of application experience and a number of patented innovations. They offer the unique ability to do comprehensive detection of surface flaws, sub-surface flaws and metallurgical properties in a single, highly stable test.

Inspection possibilities include:

  • Surface cracks and seams
  • Sub-surface inclusions
  • Grain structure
  • Material density
  • Hardness
  • Residual stresses
  • Thickness
  • Porosity
  • Alloy segregation
  • Bonding strength



100% Inspection

As a resonance technique, EMAR offers through-thickness test coverage for both physical and material defects. An innovative high speed test process allows for full integration and inline testing of finished components or continuous length wire/rod/tube/sheet.


Flexibility with Fine Defect Resolution

Small measurement areas and low-noise acoustic signals allow detection of minute defects as small as 15 microns.


Acoustically Non-Contact

EMAT sensors do not require direct contact with the test material for coupling sound waves. Short, liquid-less air gaps or soft wear surfaces eliminate common problems associated with damaged piezoelectric sensors and UT water baths. Non-contact NDT techniques consistently lower inspection cycle times and the overall costs of testing.


Continuous and Real-Time Testing

Continuous acoustic sampling with real-time signal processing provides instantaneous test feedback or defect detection. Testing can be done at material feed rates up to 2,500 feet per minute.


Compact Test Systems

Small EMAT sensors and passive test fixturing allow for safe and small-footprint implementations of test equipment into existing production processes. Offline systems can offer speedy setup for large scale production sorting or laboratory use.