Zeiss INTRABEAM, Instructions For Use Manual

Page: 58 / 82

Operation INTRABEAM Water Phantom
Version 6.2
Page 58 G-30-1767-en
Measuring isotropy
If air bubbles have accumulated on the probe tip, you must remove them prior
to the measurement, as they may negatively influence the measurement re-
sult:
•
Use a longer spatula or a plastic or glass rod to wipe off the air bubbles.
Calculating deviations
The respective deviation of the 8 measured values from their mean value di-
rectly results in the deviation from the ideal spherical symmetry in the X/Y
plane.
Measuring isotropy with spherical applicator
The geometry of the spherical radiation emission of the probe tip is checked
on an XRS 4 when measuring the isotropy. The isotropy check is performed at
maximum beam current and the beam voltage selected for the respective XRS
4.
Positioning the applicator with the XRS probe for isotropy measurement
As a rule, the isotropy of the X-ray probe is initially recorded without an ap-
plicator. It therefore can be assumed that there will be no need to completely
reposition the probe tip when measuring the isotropy with a spherical appli-
cator.
Exact positioning of the spherical applicator with the X-ray probe is a precon-
dition for accurate and meaningful measuring results.
NOTE If the user does not rotate the XRS 4 through a full 360° revolution, measured
values for the isotropy will be missing.
•
Measure in all eight detent positions in order enable determination of the
isotropy in the entire X,Y plane.