Resonance Mode EMAS Sensors




sensors in hand

The patented, Resonance Mode-Electromagnetic Acoustic Transducer sensors are what produce the narrow band resonance data and make a materials test possible. A variety of sensor designs can be used but the compact, pencil-probe type (pictured) are widely applicable and weigh less than 5 oz. each.

All EMAS' are strongly magnetic, containing rare-earth magnets. With stable test positioning magnetic fields allow for operation at lift-off distances in excess of 0.1 inches. One benefit is that EMAS signals are completely impervious to shock, mechanical noise, and vibrations that would otherwise compromise a sensitive and high speed inspection routine.

At least 1 but up to 6 sensor pairs (ARIS 3700 Series) can be used on any ARIS system. Multiple sensor testing procedures can create test redundancy for critical NDT measurements or take advantage of enhanced multi-channel test capabilities.

Sensors are delivered as a pair and we include one pair per data channel at the time of a system purchase. When selecting EMAT design specifications we consider the following test requirements:

  • Electrical impedance of the alloy being tested
  • Dimensions and geometry of the component or material
  • Minimum defect sizes
  • Sensor aperture or the size of the active measurement area
  • Allowable sensor lift-off distance



  • Precision, stainless steel sensor construction
  • Ultra abrasion and impact resistant sensor faces
  • 125 deg. C maximum ambient operating temperature
  • Cable assembly lengths up to 1000 M for remote operation
  • Requires in-line pre amplifiers
  • Requires sensor positioning fixtures that are application specific