Magnetic Tangential Field-Strength-Inspection, a Further NDT Tool for 3MA

  • G. Dobmann
  • H. Pitsch


For the real-time quality control in the production process the signification of ndt-methods is more and more increasing. In order to solve these problems within short cycle times with micromagnetic techniques (magnetic Barkhausen noise, incremental permeability) it is necessary to use excitation frequencies for alternating magnetization in the range greater than 10 Hz. According to these restrictions the fore mentioned inspection techniques are performed by the 3MA-analyzer /2/. In this range of exciting frequencies the analyzing depth of these methods is restricted to surface near material zones (ca. 300–400pm). The up to now existing 3MA-draft is expanded by two new measured quantities in the following. These quantities are derived by upper harmonic analysis in the time signal of the tangential field strength during alternating magnetization. In this case the analyzing depth is only restricted by the penetration depth of the exciting magnetic field.


Nondestructive Test Excitation Frequency Exciting Frequency Short Cycle Time Distortion Factor 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1989

Authors and Affiliations

  • G. Dobmann
    • 1
  • H. Pitsch
    • 2
  1. 1.Fraunhofer-Institut für zerstörungsfreie Prüfverfahren (IzfP)SaarbrückenDeutschland
  2. 2.Robert Bosch GmbHStuttgartGermany

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