b. Set the x-ray tube:
Longitudinally and transversely centered.
Vertically with the usual SID.
c. Position the base section of the phantom on the tabletop in the center of
d. Place the reference marker in the upper right quadrant.
e. Collimate to the phantom.
f. Place the dosimeter chamber or the digital timer contained in the light field
with a ringstand for support.
g. Place the chamber readout so it is visible to the control booth.
4-28. REPRODUCIBILITY TEST
a. Add two more pieces of Plexiglas to the base phantom for a total thickness of
six inches (see figure 4-16).
Figure 4-16. Set up for first exposure from example 4-28, a through c.