What is an Eddy Current?
Eddy currents are currents that circulate in conductors like swirling eddies (a whirlpool) in a stream. They are induced by changing magnetic fields and flow in closed loops, perpendicular to the plane of the magnetic field.
How is Eddy current used in Non-Destructive Testing?
- It is one of the electromagnetic methods of non-destructive testing.
- It is used for identifying surface and subsurface defects in conducting materials.
Principle of Eddy Current Testing:
Electromagnetic Induction is the basic principle of ECT.
How is Eddy Current used for identifying a defect?
When eddy current is induced to an object/material which is being tested, by varying the electromagnetic field alternatively, there will be a change in pattern of the current flow when a defect is present in an object.
Eddy Current Testing
Properties of Eddy Currents:
- They are induced in closed loops.
- They normally travel parallel to the coils windings.
- Its density decreases with depth.
Different types of Eddy Current Probes:
Based on the method of operation:
- Absolute probes
- Differential probes
- Reflection probes
- Hybrid probes
Based on Application: Few examples:
- Surface probes
- Rotating Scanner probes
- Manual bolt hole probes
- Bobbin probes
- Weld probes
Advantages of Eddy Current Testing:
- Surface and subsurface defects can be found.
- No physical contact is required.
- Immediate test results.
- Complex geometry can be inspected.
Applications of Eddy Current Testing:
- Aerospace Industries
- Railways
- Marine Industries
- Manufacturing Industries
- Corrosion Detection in aerospace industries, steel tubings.
To know more about Eddy Current Testing and its application; please feel free to visit our website https://aqcinspection.com/ Advanced Quality Centre, Coimbatore, NDT Training Institute for NDT Courses and Certification https://aqcinspection.com/training/
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