Multidirectional Magnetic Particle Testing
Multidirectional Magnetic Particle Testing is a special technique employed to identify defects in all orientations within a single examination. This stands in contrast to the combined magnetization shot utilized in traditional machines, which doesn’t align with ASTM standards. This technique proves effective in identifying both longitudinal and transverse cracks within one examination.
Advantages of Multi-Directional Magnetization:
Halves the time needed for testing components compared to conventional machines that require two separate shots—one for longitudinal defects and another for transverse defects.
Yields significant space and manpower savings, making it particularly valuable for high-production scenarios. This equates to a 50% reduction in resources needed.
In conventional machines, sequential magnetization is used where coil field & head shot field are applied to the part one by one with a gap of approximately 0.5 seconds. In some of the equipment the two fields even overlap for a short duration of time.
We know that the direction of magnetic field at one point in time can be in one direction only. So, when the direction of magnetic field is changed, the magnetic field generated by the first shot collapses. The indications which are formed by this magnetic field also become weak, and in some case even disappear.
The following video demonstrates this phenomenon.
Multidirectional magnetization is achieved by switching the two fields at a very high speed using advanced solid state circuitry. The switching is fast enough not to disturb the indications form by each field. Thus, indications in all the directions are shown simultaneously using this technique.
The following pictures & video demonstrates results produced by multidirectional magnetization.