What is Eddy Current Testing?

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

Applications

There are two main applications for eddy current testing, used extensively in the power and petrochemical industries.

• Surface Inspection (process vessels)
• Tubing Inspection (heat exchangers)

The technique is very sensitive and can detect small cracks. Surface inspection can be performed both on ferromagnetic and non-ferromagnetic materials.

How Does Eddy Current Inspection Work?

There are several eddy current testing methods, including:

Eddy Current Array 

This method uses an array of electrically charged coils which creates a sensitivity profile and identifies any defects within the material.

Heat Exchanger Testing 

This is one of the most common uses for eddy currents. This method works by using eddy currents to identify defects in tubes. The inspection device produces immediate results from a single pass.

Surface Array Testing 

This testing method is commonly used in the aerospace industry, but also in the oil & gas and petrochemical industries. It accurately measures conductivity, corrosion, and wall thickness, identifying defective areas which would otherwise be hard to access.