Which component is essential for generating a magnetic field in a Magnetic Particle Testing setup?

In a Magnetic Particle Testing (MPT) setup, the power supply is crucial for generating a magnetic field. The primary function of the power supply is to provide the electrical energy needed to energize the test specimen, which is often made of ferromagnetic material. When an electrical current passes through the specimen, it creates a magnetic field around it. This magnetic field is essential because it is what enables the magnetic particles to be drawn to any surface or subsurface discontinuities present in the material being tested.

Magnetic particles, while important for indicating flaws, depend on the magnetic field created by the power supply to respond and highlight any defects. The viewing medium aids in the visualization of these particles but does not contribute to the generation of the magnetic field itself. The test specimen is where the inspection occurs but, again, it’s the power supply that actually creates the magnetic field necessary for effective magnetic particle testing.