Eddy Current is also referred to as Foucault current. It is basically an electrical observable fact that was first noticed by French physicist Francois Arago in 1824. An Eddy Current occurs when a conductor is exposed to a changing magnetic field. The change in the magnetic is caused because of deviation of the field with time or relative motion of the field source and conductor. This entire process can result in circulation of electrons within the conductor. The circulating eddies or electrons of current generate stimulated magnetic fields that resist the transformation of the original magnetic field due to Lenz's law, causing repulsive or drag forces between the conductor and the magnet.
Eddy Current is not a very popular non-destructive testing method but it is widely used in testing laboratories to detect defects, sort material, test thickness and test conductivity on a wide variety of materials. Some of the application areas where Eddy current inspection is used are chilled water units, turbine condensers, weld inspection, and material sorting. It helps to identify flaws, errors, leakage, and other defects in non-ferrous tubing. Eddy current inspection is a very beneficial non-destructive testing method as it produces quick and accurate results. With the help of Eddy Current testing technique, you can easily check tube conditions on commercial air conditioning systems.
Eddy Current Instruments
Wide varieties of configurations of instruments are available for Eddy Current Inspection. In this non-destructive testing technique analog as well as digital instruments are utilized. Eddy Current Instruments are categorized by the type of display used to present the data. Here is a list of few used in the inspection process: analog meter, digital readout, impedance plane and time versus signal amplitude. Many of the Eddy Current Instruments have the feature that allows them to present data in a number of display formats.
Eddy Current Inspection Applications
Surface Breaking Cracks
SBC using Sliding Probes
Metal Thinning (Corrosion)
Heat Treat Verification
Thickness of Thin Mat'ls
Thickness of Coatings
Abcndt.com use Eddy Current in non-destructive and destructive testing methods to increase customer satisfaction and lower manufacturing costs. They cater to industries, such as automotive, aviation, construction, power plants, manufacturing, railways, military, and naval industry. ABC Testing Inc. have Certified Welding Inspectors (CWI) doing welding inspections for steel, aluminum, specialized metals like Inconel, Monel and NiAlBrz, and many other alloys. The company uses approved procedures to specific industry standard. Browse through www.abcndt.com for more information.