Improvement of the sensor system in magnetic flux leakage-type nondestructive testing (NDT)

Author

Park, Gwan Soo ; Park, Eun Sik

Author_Institution

Dept. of Electr. Eng., Korea Maritime Univ., Busan, South Korea

Volume

38

Issue

2

fYear

2002

fDate

3/1/2002 12:00:00 AM

Firstpage

1277

Lastpage

1280

Abstract

In magnetic flux leakage (MFL)-type nondestructive testing (NDT) system, the sensitivity of MFL sensor depends on the change of the magnetic field, not just on the magnitude of the field. In this paper, the leakage parameter was defined to determine the operating point in saturation curves, and an optimum design method to determine the size of the magnet to maximize the MFL signals in NDT is described. For detecting the small depth defect, we also developed the back yoke sensor system. The sensitivity of the optimum sensor system is increased up to 200%. The computed MFL signals in the optimally designed system are verified by measurement using Hall sensors mounted on the six-legged PIG in an 8-in test pipe with defects. The rhombic defects could be successfully measured and identified from the weak defect signals

Keywords

finite element analysis; flaw detection; magnetic leakage; magnetic sensors; Hall sensor; back yoke sensor system; magnetic field; magnetic flux leakage; nondestructive testing; nonlinear finite element analysis; pipeline defect detection; Design methodology; Magnetic flux; Magnetic flux leakage; Magnetic sensors; Nondestructive testing; Saturation magnetization; Sensor systems; Signal design; Signal processing; System testing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.996326

Filename

996326