Multifrequency Eddy Current Inspection with Continuous Wave Methods
This paper describes the application of continuous wave, multifrequency eddy current methods to nondestructive inspection of materials. A generalized description of the technology is included, follow~ d by s~me ~esults o~t~ined in multifrequency examination of tubing. A major advantage of multifrequency inspection is the ability to discriminate against unwanted test parameters. The discrimination process is effected by combining the data from individual frequencies in a manner similar to simultaneous solution of multiple equations. multifrequency tests are described showing how discrimination has been achieved against parameters such as probe motion, tube support plates and magnetic surface deposits.