SLOFEC
Saturated Low Frequency Eddy Current
SLOFEC™ – Saturated Low Frequency Eddy Current – is an electromagnetic technique which detects both loss of material defects caused by corrosion or erosion and small pits and cracks on the inspection surface. SLOFEC™ has been registered as a trademark by Kontroll Tecknik GmbH.
The technique is very similar to the magnetic flux leakage technique. However, instead of detecting the flux leakage with a passive coil or a hall effect sensor, the SLOFEC™ technique uses an eddy current sensor.
When applied on ferro-magnetic steels the depth of penetration of the eddy currents is very small. The flow of eddy currents in a thin layer close to the surface of the component is disturbed by defects in one of two ways: loss of material defects on the far surface alter the magnetic flux in the component which in turn alters the eddy currents; defects on the near surface directly interrupt the flow of eddy currents. The two types of response can be discriminated by measurement of the phase angle of the eddy current signal.
The SLOFEC™ inspection system is able to inspect a greater wall thickness and also able to cope with thicker non-magnetic coatings than a magnetic flux leakage inspection system.
For more information on SLOFEC™ see:
http://www.kontrolltechnik.com/
What the hec?! articles are not intended to be the definitive account on the topic or acronym in question. Readers’ comments and contributions are welcomed. Email: ndtnews@bindt.org
The technique is very similar to the magnetic flux leakage technique. However, instead of detecting the flux leakage with a passive coil or a hall effect sensor, the SLOFEC™ technique uses an eddy current sensor.
When applied on ferro-magnetic steels the depth of penetration of the eddy currents is very small. The flow of eddy currents in a thin layer close to the surface of the component is disturbed by defects in one of two ways: loss of material defects on the far surface alter the magnetic flux in the component which in turn alters the eddy currents; defects on the near surface directly interrupt the flow of eddy currents. The two types of response can be discriminated by measurement of the phase angle of the eddy current signal.
The SLOFEC™ inspection system is able to inspect a greater wall thickness and also able to cope with thicker non-magnetic coatings than a magnetic flux leakage inspection system.
For more information on SLOFEC™ see:
http://www.kontrolltechnik.com/
What the hec?! articles are not intended to be the definitive account on the topic or acronym in question. Readers’ comments and contributions are welcomed. Email: ndtnews@bindt.org
