Eddy-current testing (also commonly seen as eddy current testing and ECT) is one of many electromagnetic testing methods used in nondestructive testing (NDT) making use of electromagnetic induction to detect and characterize surface and sub-surface flaws in conductive materials.

ECT finds applications in both tubing and surface applications

• Inner-diameter (ID) pitting: excellent
• Outer-diameter (OD) pitting: excellent
• Axial cracking: acceptable, but limited
• Circumferential cracking: acceptable, but limited
• ID corrosion: excellent
• OD corrosion: excellent
• Defects at tubesheet: acceptable, but limited

• Inner-diameter (ID) pitting: good
• Outer-diameter (OD) pitting: excellent
• Axial cracking: good
• Circumferential cracking: unsuitable
• ID corrosion: good
• OD corrosion: excellent
• Defects at tubesheet: good

When it comes to surface applications, the performance of any given inspection technique depends greatly on the specific conditions — mostly the types of materials and defects, but also surface conditions, etc. However, in most situations, the following are true:

• Effective on coatings/paint: yes
• Computerized record keeping: partial
• 3D/Advanced imaging: none
• User dependence: high
• Speed: low
• Post-inspection analysis: none
• Requires chemicals/consumables: no