Planmeca Proline EC pan Technical Manual page 121

PATIENT POSITIONING MECHANISM Chapter E - DIMAX3 DIGITAL SYSTEM ADJUSTMENT
The images of 23 balls should appear on the image (Fig. 50). They should be round, all the
same size, and evenly spaced. Note that they will not necessarily be at the same vertical
height. The outermost balls on the left and right sides should appear symmetrically. If the dis-
tance from the center of the middle ball to the center of the tenth ball on the right side differs
more than 2mm from the corresponding distance on the left side, the rotation start limit must
be adjusted (in the same way as in the film-based panoramic X-ray, see section "Rotation lim-
its" on page D-22). Note, that the adjustment of the patient positioning mechanism must be
performed first. The distance from the center of the middle ball to the center of the rear middle
ball should be less than 2mm. If the distance is not correct you will have to adjust the position
of the patient positioning mechanism (see section "Patient positioning mechanism adjust-
ment" on page E-30).
R L
Figure 50
NOTE Before you can measure the true distance between the balls, you have to define a refer-
ence distance as follows:
Click the CAL button and then draw a long horizontal line to the image by clicking the
start point, releasing the mouse button and clicking the end point. The Reference dis-
tance window appears.
Calculate the line length using the formula A x 0.132mm = B, where A is the distance in
pixels and B is distance in millimetres. Enter the value B (line length in millimetres) to
the Reference distance window and click OK.
The distance from the center of the middle ball to the center of the tenth ball to the left
and the tenth ball to the right can now be measured.
The distance from the center of the middle ball to the center of the tenth ball to the left and the
tenth ball to the right should be 120mm ± 2mm. If this distance is correct then the patient posi-
tioning mechanism need not be adjusted, and you should then check the patient positioning
lights (see section "PATIENT POSITIONING LIGHTS" on page E-36).
If these distances are not correct you will have to adjust the position of the patient positioning
mechanism. The following diagrams are a rough guide as to how to position it correctly. Note
that you may have to make more than one adjustment as the patient positioning mechanism
could be incorrectly positioned in more than one direction. For example it may be too far for-
ward and too near the column.
Technical Manual
Planmeca Proline EC X-ray unit E-27