SEDL / STP / STP223-EB / STP41993S

Reduction of Probe-Spacing Effect in Pulsed Eddy Current Testing

Waidelich, Donald L.
Argonne National Laboratory, Lemont, Ill.

Pages: 10    Published: Jan 1958

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Abstract

In using pulsed eddy currents to determine the thickness of cladding, it was found that the output wave as observed on the screen of a cathode-ray oscilloscope had several unusual points. These points were stationary as the probe-to-metal spacing varied, but moved vertically as the cladding thickness changed. Tests on a clad plate seemed to indicate that the points could be used to determine cladding thickness with little interference from changes in the probe-to-metal spacing. One such method involves the use of small photocells placed in front of the oscilloscope screen with the output of the photocells connected to a recorder. The initial tests with such a system are presented in this paper.