g. Half-Value Layer Aluminum. Use pieces of aluminum of different
thicknesses to help determine the half-value layer (HVL) of a unit.
h. Star Focal Spot Test Tool. Helps determine the focal spot size (there are
only two sizes, large and small) (see figure 1-8).
i. Tomographic Phantoms. Made of Plexiglas, aluminum and other special
objects (see figure 1-9).
j. Synchronous or Electronic Milliamperage Timer. Helps determine the
accuracy of the timer by checking the milliamperage (mA) and timing. The manual spin
top test is only good on single phase units (see figure 1-10).
k. Phantom. - A model of a body or one of its parts.
l. Screen-Film Contact Mesh. Helps determine the film-screen contact. You
are looking for clear resolution (detail) (see figure 1-11).
Figure 1-8. Star focal spot test tool.