Eddy current nondestructive testing

Gutkiewicz P. "Ultrasonic and eddy current nondestructive testing in Windows envirorunent , ZfP als Dienstleitung in einer veranderten Industriestruktur, Dresden, 5-7 Mai 1997, P 67... 

Valleau. A. R. (1990), Eddy current nondestructive testing of graphite composite materials.. Materials Evaluation, Feb. 1990, 48. 2, 230-239. 

Dry film thicknesses on steel surfaces are determined by magnetic and eddy current nondestructive test instruments. The most popular instruments employ the magnetic principle measuring magnetic attraction, which is inversely proportional to the lining thickness. Examples are the BSA-Tinsley thickness gauge and the Elcometer 157 pulloff gauge. 

B. A. Auld, F. G. Muennemann and M. Riaziat, Quantitative modelling of flaw responses in eddy current testing. In R. S. Sharpe (ed.), Research techniques in nondestructive testing, Vol. 7. Academic, London, 1984. 

Nondestructive Cracks and Corrosion Testing by Eddy Current Method. 

NOTE Nonferromagnetic (metals that cannot be magnetized, such as copper and brass) tubes that are not visually accessible can be examined nondestructively using eddy current testing. 

Among the available nondestructive testing techniques are ultrasonic tests, eddy-current tests, air-underwater and hydrostatic tests, and visual examinations. All of these techniques must be executed by technically qualified personnel. 

Identification. Slag inclusions will not be visually identifiable unless slag particles emerge at the weldment surfaces. Radiography, eddy-current testing, and ultrasonics are nondestructive testing techniques that can disclose slag inclusions. 

Nondestructive testing (NDT) is used to assess a component or structure during its operational lifetime. Radiography, ultrasonics, eddy currents, acoustic emissions, and other methods are used to detect and monitor flaws that develop during operation (Chapter 7). 

The nondestructive electrical eddy current test is a method in which eddy current flow is induced in the test object. Changes in the flow by variations in the test specimen... 

Caitz, L. Nondestructive Testing Radiography, Ultrasonics, Liquid Penetrant, Magnetic Particle. Eddy Current, ASM International, Materials Park. OH, 1995 Cornua, R.D. Problem-Solving Surface Analysis Techniques. Advanced Materials Processes, 16 (December 1992). 

Corrosion detection plays an important role in any corrosion control program. Most of the methods employ nondestructive test methods and include hydrogen evaluation, radiography, dynamic pressure, corrosion probes, strain gauges and eddy current measurements. Of these, the methods employed in cooling tower practice are hydrogen evaluation and corrosion probes. 

Davis, J. M., and King. M. (1994), Mathematical formulas and references for nondestructive testing—Eddy currents, 1st ed., Art Room Corporation. 

General corrosion control, prevention, and monitoring should be planned for from the onset. To detect and monitor corrosion, various methods must be used, while corrosion protection would be done by the addition of inhibition and use of protection coatings [5]. Visual examination, laser methods, the replication microscopy liquid penetration testing method, magnetic particles testing, the eddy current inspection method, acoustic emission technique, thermal methods of inspection, and nondestructive methods are the various methods to be adopted when monitoring pipeline corrosion [5]. 

This method is based on the principle that a mechanical force is inherently associated with flow of eddy currents. Since the eddy current field is time-variant, the mechanical force is also time-variant. Therefore, an acoustic vibration can be induced in the proper sample. To use this principle in nondestructive testing of honeycomb materials, some constituents must be electrically conductive. 

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