2nd Inventors' Olympiad - GENIUS 2000 Budapest, Virtual Exhibition

Registry number: G/1-222 Category: G/1 Country: Hungary
MEASURING HEAD FOR NON-DESTRUCTIVE MATERIAL TESTING BASED ON MAGNETIC FIELD DETECTION
The invention
  • The problem to be solved: The developed nondestructive conductive material testing method combines high sensitivity magnetic field measurement with the eddy current testing (ECT) technique. It extends the frequency range of the ECT down to the hundreds of Hz and makes it suitable for the detection of the flaws in the deep region of the material.
     
  • Definition: Fluxset magnetic field sensor is placed below the exciting coil can be found in the measuring head. The sensor is located in the axis of the exciting coil, which coil axis is perpendicular to the surface of the inspected material. The exciting coil generates magnetic field and excites the investigated material while the Fluxset sensor measures the response.
     
  • Presentation: The investigated conductive material is excited by magnetic field. The local variation of the conductivity due to the effect of the flaws or any changes of the material structure has got influence on the eddy current distribution inside of the material and on the magnetic field over the surface as well. The measuring head excites the investigated material by inducing eddy currents in it and detects the perturbation of the magnetic field close to the surface. The applied sensor measures the vector-components of the magnetic field and provides the two or three dimensional field map over the scanned area.

Map of the measured magnetic field over the surface

  • Application: Fast, touch-less, non-destructive testing of conductive materials which has got high conductivity and/or thick walls.
     
  • Advantages: This technique keeps the benefit of the high sensitivity and spatial resolution in the low frequency range when the exciting magnetic field can penetrate into the deep region of the investigated material and can get information about the micro flaws are located far from the surface. The developed probe offers significantly more information about the perturbations of the eddy current distribution inside the material. It detects the vector components of the magnetic field in each point of the inspected specimen surface despite of the impedance coil measurement is based on the interaction of the exciting-detector coil and the material, which can get information only from about the whole area of the detector coil. The separation of the magnetic field detection and the eddy current excitation makes possible to take apart the spatial resolution and sensitivity of the probe from the applied frequencies for the eddy current induction.
     
  • Stage of development: Prototype.
     
  • Documentation available: Several experimental results, detailed description.

2. The inventor(s)

  • Csaba Sándor Daróczi, researcher, Research Institute for Technical Physics and Materials Science
  • Antal Gasparics, researcher, Research Institute for Technical Physics and Materials Science
  • János Szöllősy, developer and inventor of the Fluxset sensor
  • Gábor Vértesy, researcher, Research Institute for Technical Physics and Materials Science

3. The protection

  • Form: Exibition priority
  • Priority: May 4, 2000
  • Countries where it is in force:

4. Business intention

licence sale (possible co-operation, investor participation)

5. Contact

Name: János SZÖLLŐSY
Phone: +36 30 924-5399
Fax: +36 1 392 2222/1740
E-mail: szjanos@ns.kfkipark.hu
Address: H-1121 Budapest, Fulemule 12/7B - Hungary