Villa Rotograph EVO, Service Manual

Page: 84 / 223

SERVICE MANUAL
Maintenance and servicing
(Rev. 1) Rotograph EVO 7-13
7.2.2.3. Soft Tissue Filter (STF) adjustment
The Soft Tissue Filter (STF) may be adjusted depending on the end user's
requirements which may call for more or less evidence of the patient's
profile; usually this is done after performing several radiographs.
To perform the adjustment:
1. Set the unit in Ceph function, selecting one of the two lateral exams.
2. Check that the cephalostat assembly is in the latero-lateral position.
3. Insert a cassette with an unexposed film accordingly with the
selected projection.
4. Perform an exposure at 60kV – 6mA – 0.4sec and develop the film.
Depending on the projection to be adjusted, act on filter "I" (Figure 7-5)
for 18x24, 8"x10" or 24x30 Asymmetrical projection and/or on filter "L"
(Figure 7-5) for 24x18, 10"x8" or 30x24 Asymmetrical projection,
loosening the two filter fixing screws (without removing them) and move
by hand the STF until the radiographic image is according with the user
requirements.
Consider that a 1mm (0.04") adjustment on the filter will result in a
15mm (0.6") variation on the film.
I
L
Figure 7-5