Eddy Current Testing signals of the transmission/receiver (TR) type probe can be influenced by the directivity of the probe. In the previous study, ECT signal change due to scanning angle was evaluated in ferromagnetic material using a TR type probe, but the mechanism of the change is still not clear. In this study, ECT is conducted changing the orientation of the TR probe both on carbon steel and on austenitic stainless steel, to investigate the mechanism. The results show that the directivity of the probe...

We examined the detection method of cracks in the lower layer of cladding of the nuc lear reactor pressure vessel, and tried an application of eddy current testing. The cladding processing produces noise by magnetic permeability. By this study, we devel oped a uniform eddy current probe aimed at detecting cracks of the pressure vessel....
英字タイトル:
Development of eddy current probe for crack detection under SUS cladding

This paper aims at a detecting corrosion on the back surface of a ick steel plate. Our proposed technique is characterized by using pulsed eddy current testing with DC magnetization. The thick steel plate is magnetized by DC Magnetizer. Therefore the magnetization g erates the magnetic flux in the plate. The permeability of the plat e changes with the corrosion. Changes in the permeability of the pl ate are detected by pulsed eddy current testing. The corrosion on e back surface of the plate was detecte...
英字タイトル:
Corrosion Detection on Steel by using Pulsed Eddy Current Testing

In this research, a uniform eddy current multi-probe to apply to the complex structure and inspect the cracks at high-speed data ac quisition was developed. Pick-up coils of the developed probe were arranged on a flexible printed circuit board. It was confirmed t hat the SCC (stress corrosion cracking) of real flaw was able to be detected with developed uniform eddy current multi-probe by usin g the ferrite core for the exciting coil and considering the impedance matching of the exciting coil and the flaw ...
英字タイトル:
Development of uniform eddy current multi-probe and characteristic evaluation of SCC detection

In yoke method magnetic-particle testing, it is necessary to perform the testing at least two times by changing the direction of magnetization. In a rotating field type magnetizer using a three-phase al ternating current (AC), any directional flaw can be detected by a single testing. In this research, the distributions of the rotating magnetic flux density were evaluated by measuring this density using Hall elements (in three directions) and by numerical analysis. The distributions of the magnetic flux den...
英字タイトル:
Evaluation of generated field in magnetic-particle testing using rotating field

This paper is motivated by the desire to evaluate thickness of zinc layer on steel in a manufacturing process of zinc plating. A short distance between a blower for blowing liquid zinc and a sensor for measuring thickness of the layer, and a long distance between the sensor and test samples are required in the process. We have tried to apply the eddy current testing for measuring thickness of a zinc layer with vibration. This paper shows the calculated phase dependencies of an eddy current sensor on the th...
英字タイトル:
Measurement of Plating Thickness with Vibration by Eddy Current

In a nuclear power plant, when external stresses such as huge earthquake are added, residual strain may have occurred in the structure. In this researc h, SUS316L and SS400 which applied the stress and added residual strain, are created, and the possibility of diagnosing of the residual strain nondestr uctively from the magnetic characteristic of test pieces are examined. The basic magnetic characteristics were measured by a coil wound up the specimen directly, and the nondestructive measurements were carr...
英字タイトル:
Magnetic Characteristic of Strain Metal Materials

This paper aims at detecting thinning of the back surface of a steel double sided structure. Our proposed technique is characterized by using pulsed eddy current testing with DC magnetization. When a double structural steel is magnetized by DC current, flux leakage is generated as a result of thinning on the back surface. We have shown by the use of simulations that the permeability of the top plate has changed with flux leakage from the back plate. The steel plate without thinning and the steel plate...
英字タイトル:
Detecting Thinning on Back Surface of Double Structure of Steel by Pulsed Eddy Current Testing with DC magnetization

We developed a novel non-destructive inspection method of the pulsed electromagnetic force acoustic method (PEFAM) for diagnosis of condition of reinforcing bars in reinf orced concrete. It is characteristicf this method to use a pulsed electromagnetic force caused by discharge using condenser bank. The orce can generate acoustic waves to a reinforcing rod in the reinforced concrete. Acoustic sensors attachedn the surface of the reinforced concrete detect the acoustic waves. The detected waves include much...
英字タイトル:
Diagnosis of Reinforced Concrete by Electromagnetic Force