PTW NORMI 13, User Manual

Page: 16 / 43

NORMI 13 (T42023)
Operating Manual - Preparing the Constancy Test
16 D703.131.00/03 en
2.3 Test Setup
The NORMI 13 test object is intended for tests in
compliance with the standard, employing a PMMA
and copper absorber or an aluminum absorber.
The test setup with a PMMA absorber is shown
in
Figure 3 . The test setup with an aluminum
absorber is shown in Figure 4 .
•
Position the test object as close to the image
receptor of the application device as possible.
The center of the test object should be located
in the middle of the radiation beam.
– Over-couch tubes:
Place the test object on the patient couch
with the measuring plate facing up. The
FOCUS label points upward.
– Under-couch tubes:
Screw the four standoffs to the measur-
ing plate and place the test object on the
patient couch with the measuring plate fac-
ing down. The FOCUS label points down-
ward.
– Wall bucky:
Use the bucky mounting device (T20005)
to fasten the test object and the PMMA
absorber (refer to
4.1 "Use of the Bucky
Mounting Device T20005 with a Test
Object"
). If the test object is used in com-
bination with the aluminum absorber, the
wall stand holder is needed in addition to
the bucky mounting device (refer to
4.2
"Use of the Wall Stand Holder T20018 with
Bucky Mounting Device T20005 and Test
Object"
).
•
Center the test object relative to the X-ray tube
and adjust the light field indicator to the edge
marks of the test object. During this procedure,
line up the edge of the light field and the four
line marks of the test object.
HINT
If there is no light field indicator, the test
object can be centered relative to the radi-
ation field on the image display device by
means of fluoroscopy control.
•
Using the supplied reclosable fastener, attach
the dose detector to the dose measurement
area (
1
, Figure 2 ). Make sure that neither the
dose detector nor the detector cable cover any
of the test elements.