Specifications

3.2.1 Remove the LINEAR collimator table-top TEST PATTERN #1 from this manual
and position it on the table-top with the edges parallel to the table-top edges.
Flatten the creases and tap it into position at the corners in a manner that will
not damage it upon removal.
3.2.2 Angulate the collimator to 0° horizontal. Position the collimator at a focal spot to
TEST PATTERN distance of 100 cm + 0.2 cm by measuring from the center of the
exit window to the center of the light-field; this distance should be 77 cm + .02 cm”.
LIGHT FIELD/X-RAY CONGRUENCE TEST
3.2.3 Place the X-Ray source to table distance at 100 cm SID.
3.2.4 Locate a cassette on the table-top and accurately center the cassette to the light-
field.
3.2.5 Manually reduce the size of the X-Ray field to the next smaller film size.
3.2.6 Identify the light-field edges and carefully mark the edges by placing the metal
markers as illustrated in Figure 3.1.
3.2.7 Expose the film to a density of 1.0 and develop.
3.2.8 Carefully identify the X-Ray field edges and measure the difference between the
X-Ray field edges and light-field edges.
3.2.9 The sum of the long axis difference (X1 + X2) shall not exceed 2% of the SID,
and the sum of the cross axis difference shall not exceed 2% of the SID.
3.2.10 If errors exceed those shown in Figure 3.1 below, refer to Section 4.0,
ADJUSTMENT AND ALIGNMENT PROCEDURES.
November 2005 ( 3-4 ) Linear MC150-C Collimator