Testing arrangement for ferromagnetic bodies including magnetic field detectors extending between two pairs of poles of magnetic field generators spaced longitudinally along the body

US4538108A · kind A · utility

Assignee

• Nukem, LLC · DE

Inventors

• Gerhard Huschelrath · Laufach, DE
• Wilfried Lein · Hanau, DE

Key dates

• Filing date: Aug 16, 1982
• Grant date: Aug 27, 1985
• Expiry date: Aug 16, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/82
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus for non-destructively testing ferromagnetic bodies to determine structural irregularities by means of magnetization of the respective object, comprises detectors for magnetic fields arranged close to the surface of the body, by which detectors any changes of behaviour of the magnetic field caused by structural irregularities can be determined. At least two stationary magnetic fields are arranged one after the other on the body that can be displaced in its longitudinal direction, the center axes of these magnetic fields being inclined toward each other at an angle. This angle is determined by the number of magnetic fields and is equal to the quotient from one hundred and eighty degrees and the number of magnetic fields. In the space between the poles of the magnetic field generators, the magnetic field detectors are stationarily arranged and in rows, each extending over a zone being equal to a body section to be tested, vertically to the shifting direction of the body. The outputs of the magnetic field detectors are connected time-multiplex to an evaluation circuit.