Which of the following statements about magnetic particle testing is false?

The statement asserting that the best results in magnetic particle testing are obtained with parallel magnetic flux lines is indeed not accurate. In magnetic particle testing, it is crucial for the magnetic flux lines to converge at the location of a potential flaw, which is often best achieved when the magnetic field is oriented in a way that is transverse to the plane of the defect. This alignment allows for a more effective indication of defects as the magnetic particles tend to gather at these lines of flux concentration, making the defective areas more visible.

In contrast, the other statements regarding magnetic particle testing are true. This testing method is adept at identifying both surface and subsurface defects, thereby providing a comprehensive indication of the material's integrity. The use of fluorescent particles does indeed enhance sensitivity, particularly under ultraviolet light, allowing for easier detection of fine flaws. Finally, magnetic particle testing is notably less effective in wet conditions, as moisture can interfere with the detection process and reduce the visibility of the magnetic particles, hindering the overall effectiveness of the inspection.