Proceedings of E'NDE '96, October 28-29 (1996) Tokyo, Japan (submitted)
Eddy current testing with fluxset probe
J. Pávó(1), Antal Gasparics(1), Imre Sebestyén(1), Gábor Vértesy(2), Csaba S. Daróczi(2) and Kenzo Miya(3)
(1) Dept. Electrmagnetic Theory, Technical University of Budapest, H-1521 Budapest, Egry J. u. 18., Hungary
(2) HAS, Research Institute for Materials Science, H-1525 Budapest, P.O. Box 49, Hungary
(3) Nuclear Engineering Research Lab., University of Tokyo, Tokai-mura, Naka-gun, Ibaraki, 319-11, Japan
In this paper a novel type of eddy current testing (ECT) probe design
is presented. The probe consists of two exciting coils used for the
induction of eddy current in the tested specimen and a fluxset sensor
measuring the perturbation of the magnetic field due to the presence
of inhomogeneity in the tested material. The operational principle of
the fluxset sensor is discussed highlighting its capabilities for the
measurement of DC, AC and time-dependent magnetic fields. Beyond the
high sensitivity, the advantage of the application of fluxset sensor
for ECT measurements is the fact that, until a certain upper frequency
limit, its sensitivity is almost independent of the frequency of the
measured field, consequently it can be used for measurements where
high penetration depth is required for the test of the specimen.
Experimental data taken by the fluxset probe on a cracked stainless
steel plate is presented. An optomisation method is also discussed
that can be used for the enhancement of the sensitivity of the fluxset
sensor by varying the shape of the ferromagnetic core of the sensor.
The optimisation is demonstrated by a numerical example.