Experimental study on flaw detectability of remote field eddy current testing

For the purpose of comprehending the effect in practical use of the remote field eddy current (RFEC) testing that becomes noticeable for the ISI technique of steel tubes, its flaw detectability was clarified through a model test. This study used straight and bending tubes of 3.8 mm in wall thickness and 31.8 mm in outside diameter. These tubes were inspected from their inside. After relations among the pickup coil output, coil distance, testing frequency, etc. were measured, a probe of the practical use type was manufactured to investigate its flaw detectability by means of simulated flaws. The authors discuss how it has been found that light local wall thinning on the outside surfaces can be detected by this technique and its effect in practical use can be expected with small influences due to magnetic permeability variations of tube materials, bending of tubes, etc