Specifications

B. EQUIPMENT
1. Plastic cassette with direct printer paper or film.
2. Radio-opaque markers*
* Each marker is approximately .080 cm galvanized sheet metal having the dimensions of
4 by 4 cm.
C. PROCEDURE
1. Adjust the source assembly and the beam-limiting device so that they are
approximately centered over the table and perpendicular to the table top.
Then position the beam-limiting device to the SID previously determined
and record the indicated value.
2. Insert the cassette and turn on the light-field.** Adjust the beam-limiting
device to the next size smaller than the cassette size being used.
** Make a note to record the field size indicated on the dial of the beam-limiting device
for the SID being used.
3. Position the outer edge of each metal marker on the table top to
correspond with each side of the light-field (Figure 5-5).
4. Select the appropriate technique factors and make an exposure.
5. Develop film or direct-print paper.
D. VERIFICATION OF COMPLIANCE
For determination of misalignment, compare the edges of the X-Ray field to the
edges of the light field as defined by the outer edges of the metal strips. On
each side of the rectangular fields, measure the separation between the X-Ray
field and the outside edge of the image of the respective metal strip. Sum these
measured separations for opposite sides of the X-Ray field to yield a total
misalignment in the length and width dimensions. Record the length
misalignment and width misalignment, both without regard to sign (see Par. E
and Figure 5-3 ).
November 2005 ( 5 - 12 ) Linear MC150-C Collimator