What are the limitations of eddy current testing?

Disadvantages: Method restricted to conductive materials. Inspection of ferromagnetic materials can be impacted by magnetic permeability. Depth of inspection (penetration) is limited.

What is eddy current testing in NDT?

Eddy current testing is a non-destructive testing (NDT) inspection method used for a variety of purposes, including for flaw detection, material and coating thickness measurements, material identification and establishing the heat treatment condition of certain materials.

What are the factors affecting eddy current?

The frequency of the alternating current passing through the eddy current test coil affects the depth of penetration of the eddy current field in the test material. This is also known as the skin effect. The intensity of the eddy current flow will decrease exponentially with increasing depth into the material.

What are the applications of eddy current testing?

Typical applications for eddy current testing include:

• Crack detection.
• Tube and wire testing.
• Condenser tube inspection.
• Material sorting.
• Weld testing.
• Coating thickness measurement.

What are the advantages and disadvantages eddy current?

Answer:Advantage:- Eddy currents can be induced in a metal plate by passing into magnetic field. Disadvantage:- But in case of transformer it this current will cause heat loss.

What is eddy current technology?

Eddy current technology is an electromagnetic technique widely used in the aerospace, automotive, petrochemical, and power generation industries for the inspection of metallic structures. In this technique, the probe, which is excited with an alternative current, induces eddy current into the part under inspection.

What is the advantage of eddy current?

The advantages of eddy current testing are: Sensitivity to surface defects. Able to detect defects of 0.5mm in length under favourable conditions. Can detect through several layers.

What are the factors affecting eddy current testing?

There are several factors that affect the accuracy of an eddy current inspection. These are testing frequency, alignment of flaws, lift-off, and surface geometry.

What are the factors affecting eddy current inspection and mention its various applications?

By drawing and studying the cause-effect diagram factors affecting eddy current testing and the explored difficulties with ECT are found as varying conductivity within workpiece, homogeneity of workpiece material, flatness, porosity, surface roughness, orientation of defects, location of defects, measurement error.

What is the main reason for the limitation of depth below 6mm in eddy current inspection ECI?

Explanation: Eddy current causes skin effect. It restricts to a depth below 6mm. Skin effect is the reason for the limitation of depth below 6mm in ECI.

Which of the following is a disadvantage of magnetic particle testing?

Disadvantages of the Magnetic Particle method of Non-Destructive Examination are: It is restricted to ferromagnetic materials – usually iron and steel, and cannot be used on austenitic stainless steel. It is messy. Most methods need a supply of electricity.

How can the disadvantages of eddy currents be minimized in transformers?

Eddy currents are minimised by using laminations of metal to make a metal core. The laminations are separated by an insulating materials like lacquer. The plane of the lamination must be arranged parallel to the magnetic field, so that they current acroos the eddy current paths.