Eddy Current

Description:
Eddy Current Testing (ECT) uses electromagnetic induction to detect flaws in conductive materials. This testing is widely used in nuclear, aerospace, power, petrochemical industries for detection and sizing of cracks, corrosion and other material discontinuities during manufacturing as well as in-service inspection.

Inspectest by means of its skilled staff and state-of-the-art Advanced Eddy Current flaw detector (multi-frequency and multi- channel) offers an unmatched portable unit with advanced features and functions to our valuable customers.

Applications:

• Eddy current coil generates primary magnetic field (Ampere’s law)
• Primary magnetic field induces eddy currents in the material (Faraday’s law)
• Eddy currents generate secondary magnetic field in the opposite direction (Lenz’s law)
• Coil impedance changes, as a result Impedance change is measured, analyzed and correlated with defect dimensions

Our ECT equipment has the latest analysis software which has been verified on reference calibration standard. The software enables our inspection to get direct percentage wall loss valves and is capable of fast data acquistion.

Tube Inspection:
Tube inspection is performed by inserting an internal differential probe down the full length of each tube being inspected and observing the eddy current response on the test instrument screen. Coils located in the inspection probe produce an electromagnetic field which are affected by changes in the tube wall such as wall loss and pitting etc.

Advantages:
Quick, simple, and reliable inspection technique to detect surface and near-surface defects in conductive material
Can be used to measure material electrical conductivity
Measurement of nonconductive coating
Hole inspection with the use of high-speed rotating scanner and surface probe

• Sensitivity to surface defects. Able to detect defects of 0.5mm in length under favorable conditions.
• Can detect through several layers. The ability to detect defects in multi-layer structures (up to about 14 layers), without interference from the planar interfaces.
• Can detect through surface coatings. Able to detect defects through non-conductive surface coatings in excess of 5mm thickness.
• Accurate conductivity measurements. Dedicated conductivity measurement instruments operate using eddy currents.
• Can be automated. Relatively uniform parts can be inspected quickly and reliably using automated or semi-automated equipment, e.g. wheels, boiler tubes and aero-engine disks.
• Little pre-cleaning required. Only major soils and loose or uneven surface coatings need to be removed, reducing preparation time.