Which of the following NDE methods is not suitable for detecting surface breaking cracks?

Profile Radiography (Profile RT) is not suitable for detecting surface-breaking cracks because this method primarily focuses on volumetric examination rather than surface conditions. It is designed to provide images of the internal structure of a material, revealing discontinuities like voids, inclusions, or wall thickness variations within the bulk of the material. While Profile RT can show some surface features, it is not ideal for identifying fine surface-breaking cracks because it does not offer the sensitivity or resolution needed for such small discontinuities.

On the other hand, methods like Ultrasonic Testing, Magnetic Particle Testing, and Dye Penetrant Testing are specifically tailored to detect surface irregularities. Ultrasonic Testing can identify cracks just beneath the surface, while Magnetic Particle and Dye Penetrant Testing are more directly focused on surface anomalies. Hence, Profile RT stands out as the method that does not align with the requirement of detecting surface-breaking cracks effectively.