Geometric unsharpness
Geometric unsharpness is the fuzzy edge on X-ray images caused by focal spot size and distance. It is minimized by special test setups.
Physicochemical Mechanism of Action
Geometric unsharpness arises because the X-ray beam is projected through a finite focal spot onto the specimen. Additionally, distances and angles between the source and film contribute to additional blur.
Metallurgical Relevance & Welding Risks
High geometric unsharpness can lead to inaccurate measurements, which is critical especially in weld quality and material structure testing. Inaccuracies can lead to misjudgments in quality assurance.
Workshop Practice & Action Instructions
To minimize geometric unsharpness, use:
• A small focal spot as possible (high X-ray energy)
• A short source-to-specimen distance
• Special test setups with fixed distances and angles
These measures ensure more accurate radiographs and improve inspection accuracy.