Determination of length and position of an object which cannot be seen

This experiment provides training in determining the length and position of an object based on an X-ray image. A metal pin that is embedded in a wooden block is used as the model. This experiment is also an excellent preparatory exercise for demonstrating the principle of computed tomography.

Benefits

• Simulation of a real-life situation in x-ray diagnostics
• Application which trains three-dimensional thinking

Tasks

1. Record a bi-planar radiogram of two perpendicular planes of a metal pin which cannot be seen.
2. Determine the true length of the pin by taking into account the magnification factor which results from the divergence of the X-rays.
3. Determine the spatial position of the pin.

Learning objectives

• X-ray radiation
• Bremsstrahlung
• Characteristic radiation
• Law of absorption
• Mass absorption coefficient
• Stereographic projection