Ronald E Mitchell

US Patent:

51666278, Nov 24, 1992

Filed:

May 30, 1991

Appl. No.:

7/707538

Inventors:

Thomas J. Kikta - Pittsburgh PA
Ronald D. Mitchell - Pittsburgh PA

Assignee:

The United States of America as represented by the United States
Department of Energy - Washington DC

International Classification:

G01R 2708

US Classification:

324718

Abstract:

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet.