Patent US3902125A successfully refreshed from Google Patents.
Patent EP0090482A1 successfully refreshed from Google Patents.
EP0090482A1
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EP
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Apparatus for measuring defects in insulation coatings
Assignee: British Gas Corp
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Filing: 1983-01-26
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Granted: —
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Expires: 2003-01-26
Abstract
Abstract Apparatus for measuring defects in insulative coatings, eg insulating coatings applied to buried pipes comprises an AC signal generator and pairs of receiver transducers responsive to the magnetic flux associated with the generated AC signal and signal processing means for comparing the magnetic field strengths at the location of each transducer. A current gradient is obtained by comparing the field strength differences at two different points by utilizing two pairs of transducers whose axes are aligned tangentially coincident with the magnetic field. A guidance system is also provided using a pair of transducers whose axes are radially aligned with respect to the pipe.
Inventors
- 👤 Raymond Toomer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 13:40
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/02; G01V3/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
102 words
Apparatus for detecting defects in electrically insulating coatings which apparatus includes means for generating and supplying an alternating signal current to a coated conductor and means for detecting and measuring the alternating magnetic field associated with said signal current, to infer the magnitude of the signal current characterised in that said detecting and measuring means comprises a pair of identical transducers arranged in a spaced-apart parallel relationship in a plane normal to the conductor axis and associated means for receiving, comparing and processing signals induced from each transducer in response to magnetic flux to infer the magnitude of the said signal current.
Claim 2
Dependent Claim
102 words
Apparatus for detecting defects in electrically insulating coatings which apparatus includes means for generating and supplying an alternating signal current to a coated conductor and means for detecting and measuring the alternating magnetic field associated with said signal current, to infer the magnitude of the signal current characterised in that said detecting and measuring means comprises a pair of identical transducers arranged in a spaced-apart parallel relationship in a plane normal to the conductor axis and associated means for receiving, comparing and processing signals induced from each transducer in response to magnetic flux to infer the magnitude of the said signal current.
Claim 3
Dependent Claim
11 words
Apparatus as claimed in Claim 1 wherein said transducers are coils.
Claim 4
Dependent Claim
69 words
Apparatus as claimed in Claim 1 or Claim 2 characterised in that said detecting and measuring means comprises a further pair of transducers whose axes are in a plane normal to the conductor axis and longitudinally displaced from the plane of the first pair and said associated means is arranged to compare the signals induced from each pair of transducers to infer the signal current gradient within the conductor.
Claim 5
Dependent Claim
32 words
Apparatus as claimed in any one of Claims 1 to 3 wherein said alternating signal current is of a diferent frequency to the frequency of any electrical current flowing along the conductor.
Claim 6
Dependent Claim
85 words
Apparatus for the location of remote electrical conductors including means for generating and supplying an alternating current signal to a conductor and means for detecting the alternating magnetic field associated with said signal current, characterised in that said detecting means comprises a first transducer whose axis is substantially horizontal, second and third transducers whose axes are angularly disposed both to the horizontal and to the vertical, and associated signal processing means for receiving and comparing signals induced in each transducers in reponse to magnetic flux.
Claim 7
Dependent Claim
85 words
Apparatus for the location of remote electrical conductors including means for generating and supplying an alternating current signal to a conductor and means for detecting the alternating magnetic field associated with said signal current, characterised in that said detecting means comprises a first transducer whose axis is substantially horizontal, second and third transducers whose axes are angularly disposed both to the horizontal and to the vertical, and associated signal processing means for receiving and comparing signals induced in each transducers in reponse to magnetic flux.
Claim 8
Dependent Claim
11 words
Apparatus as claimed in Claim 5 wherein said transducers are coils.
Claim 9
Dependent Claim
38 words
Apparatus for location and detection of insulation defects in electrical conductors comprising detection apparatus as defined in any one of Claims 1 to 4 in combination with location apparatus as defined in either Claim 5 or Claim 6.
References Cited (Backward Citations)
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