Types of Stationary Grids

• Types of Stationary Grids (portable)?

  1. Parallel Grid
  2. Focused Grid
  3. Crosshatch Grid
• Parallel Grid is non-focus, and linear
• Focused Grid matches the divergence of the beam
• Crosshatch Grid is linear in both ways (longitudinally and transversely)
• With cross hatch grids excellent efficiency is needed

  • precision centering
  • no tube angle
  • no IR angle

  A 8:1 grid would be better to use as it will give a lesser margin of error compared to a 16:1 or 12:1 grid ratio