TOP-X100NR USER MANUAL
Innomed Medical Inc.
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High-speed rotation can be turned on with any exposure parameter settings. It can
only be turned off if the current settings do not overload the tube at normal speed.
7.2.4 FOCUS – X-ray tube focal spot
Use this button (32) to select one of the usually two possible X-ray tube focal spots
you would like to use:
•
S
mall focal spot
Results in a sharper image, but cannot be loaded as much as large focal
spot and takes higher thermal stress for the anode plate.
•
L
arge focal spot
Results in a less sharp image, but can be loaded more than small focal
spot.
Selection depends on the parameters required for the examination and X-ray tube
load ability. Of course the generator takes into account the applied X-ray tube’s load
ability, so it does not allow to set any parameter combinations that exceed the limit
values.
During exposure parameter setting the generator automatically sets the appropriate
focal spot. Manual switching is only possible if the set parameters are allowed at
both focal spot settings.
In mAs mode when using the FOCUS button if the selected parameter combination
is not allowed with the selected focal spot, the generator will try to recalculate the
current (mA) and time (s) values without changing the mAs value. In this case the
mAs and the kV values are not changed.
In three-point mode manual focal spot selection is only possible in a very small
parameter range.
A LED over the button indicates the focal spot selected for the exposure.
7.2.5 Automatic selection of large focal spot and high-speed rotation
The X-ray image quality is better if the exposure is made on small focal spot. The X-
ray tube can sustain larger loads at large focal spot or high-speed. During increasing
the load the generator automatically switches to large focus or high speed for larger
load ability.
In the configuration you can set whether the generator should first try to switch to
large focal spot or high-speed. If you select keeping small focal spot, the advantage
is a better resolution image. If you select keeping normal speed, the advantage is
less load on the anode and less heat transmitted into the tube.