What is the purpose of using a magnetic particle wet suspension in MPT?

Using a magnetic particle wet suspension in Magnetic Particle Testing (MPT) primarily focuses on the mobility and distribution of magnetic particles during the inspection process. A wet suspension allows the magnetic particles to disperse evenly across the surface of the part being tested. This improved mobility is crucial for ensuring that particles can easily flow into any surface defects, such as cracks or voids, which may not be as effectively reached by dry powders. The wet suspension creates a medium that allows particles to cling and highlight any discontinuities that might not otherwise be visible if the coverage were insufficient.

While other options present potential benefits of different inspection methods or techniques, the enhancement of particle mobility is the primary reason for the use of a wet suspension, as it directly contributes to the sensitivity and effectiveness of the detection process in MPT.