Non-Destructive Testing (NDT) Practice Test

Which description best fits the methods and techniques used during magnetic particle inspection labs?

1. Direct, longitudinal, continuous dry

2. Indirect, longitudinal, continuous wet

3. Direct, transverse, discontinuous wet

4. Indirect, transverse, continuous dry

The correct answer is: Indirect, longitudinal, continuous wet

The methods and techniques used during magnetic particle inspection, particularly in lab settings, involve the assessment of the magnetic fields created in ferromagnetic materials when inspected. The correct answer features "indirect, longitudinal, continuous wet" as a fitting description. In magnetic particle inspection, the use of a wet medium to carry the magnetic particles allows for better dispersion and visibility of discontinuities like cracks or inclusions on the surface of the test object. This is particularly important to reveal defects that lie near the surface without requiring contact or specific orientation of the testing equipment, which is why the term "indirect" is appropriate. The "longitudinal" aspect refers to the magnetic field orientation, where the magnetic field is aligned along the length of the part being tested. This ensures that any surface defects aligned with this axis can be detected effectively. The continuous nature signifies that a constant flow of magnetic particle suspension is maintained throughout the inspection process, enhancing the detection capability and providing immediate visualization of any identified flaws. These elements combined make Option B the best choice for describing the methods and techniques used effectively during magnetic particle inspection labs.