Back to results
US 4,048,558 AGranted
Method and apparatus for detecting metal failures in situ
OwnerClark Goodmaninventor
Life of this patent
Estimating the term…
Abstract
Metal failures are detected in situ, for example, in the piping system of a nuclear reactor or a pipeline by passing a current through the metal in which the failures are to be detected at various frequencies and monitoring the impedance. By using various frequencies the present invention makes use of the skin effect thereby enabling, through detection of differences in impedance at different frequencies the determination of the depth of a crack or the like in the metal.
Claims36
A method of detecting metal failures in situ comprising:
- a. conductively coupling an electrical generator to a section of metal to be tested to form a closed conductive circuit;
- b. passing currents at different frequencies through said section of metal to be tested;
- c. measuring at least one electrical characteristic of the circuit at each of said different frequencies;
- and
- d. comparing said at least one characteristic with a previous value of that characteristic whereby the presence and depth of a failure in said metal can be detected by determining the frequencies at which a change in said characteristic is found.
2 more elements
Apparatus for detecting metal failures in situ comprising:
- a. generating means for providing output currents and voltages at different frequencies;
- b. means conductively coupling the output of said generating means across a section of metal to be tested to form a closed conducting circuit;
- and
- c. means for measuring an electrical characteristic of said circuit for each of a plurality of frequencies output by said generating means.
1 more element
Dependencies are inferred from the claim text.