Zeiss INTRABEAM, Инструкция по эксплуатации

Страница: 60 / 82

Operation INTRABEAM Water Phantom
Version 6.2
Page 60 G-30-1767-en
• Observe the current value reading on the electrometer display and move
the spherical applicator further upwards. You can see that the current
value increases accordingly.
• If you move the spherical applicator together with the X-ray probe further
upwards and the current value drops, you have passed the exact target
point.
• Move the spherical applicator together with the X-ray probe back down
slightly and vary your setting in the Z axis until you have set the maximum
current value.
• In the position with the maximum current value, you have reached the ex-
act Z position of the spherical applicator (and of the probe tip).
• Secure this Z positioning using the locking lever on the adjusting knob for
the Z axis.
The isotropy measurement is performed by rotating the XRS 4 through one
full revolution while measuring the emitted X-ray radiation.
• Position the rotary feedthrough in the 8 detent positions.
The procedure for positioning the rotary feedthrough is explained on
page 57.
• Determine the isotropy and calculate the deviations.
The procedure for determining the isotropy and calculating the deviations
is explained on page 58.
Recording the depth dose curve with a flat applicator or
surface applicator
Exact positioning of the applicator (with the probe tip) is a precondition for
accurate and meaningful measuring results.
• Do not adjust the positioning unit in the X and Y axes.
• Unless this has already been done:Note down the previously determined
value of Z
1
[mm], see page 41.
• Release the locking lever on the adjusting knob for the Z axis.
• Place the positioning unit all the way up in the Z axis.