Checking The Dose Rate Values - Siemens ARCOSKOP Troubleshooting Manual

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NOTE
NOTE
Correction factors
Grid correction factor:
Dose measuring chamber correction factor:
Prerequisites
System in normal mode - no service functions active.
KV-Stop is not active. The LED of the KV-Stop button is off.

Checking the dose rate values

WARNING
NOTE
ARCOSKOP
System Manual
If a dose measuring instrument with solid-state detector is used,
take care that the solid-state detector lies outside the dominant of
the dose rate control.
The dominant has a diameter of approx. 6 cm in relation to the
monitor screen.
The dose measuring chamber correction factor is not to be taken
into account in this case. Then calculate the dose rate on the
image intensifier input screen from [measured dose rate (nGy/s) /
grid correction factor] and compare it with the table.
For measurements with zoom format:
Take care that the dose measuring chamber is irradiated over its
entire area. Check the centering of the dose measuring chamber
with zoom format selected.
X-ray radiation!
See Chapter 1, Safety Information.
Use radiation protection. Wear a lead apron when making the
checks! Keep the fluorotime as short as possible. Maintain a safe
distance!
The ADC control characteristics are calculated for water values.
There is a lower scattered radiation proportion if copper is used
as prefilter.
The kV/mA transfer values on changing over the operating modes
are therefore subjected to larger tolerances.
Thus after changing over the operating modes and releasing
radiation, wait until the dose or dose rate value control has stabi-
lized again.
After changing over to the DR mode with a programmed K factor
of k > 1, release at least 2 exposures before the dose measure-
ment until the dose control is adjusted (= no further change of the
kV/mA display values).
After changing over to the EB mode (= DR mode with k=1) release
approx. 2 to 5 exposures until the dose control is adjusted
(= no further change of the kV/mA display).
SPR2-250.840.01
Rev. 01
Adjustments / Programming
1.5
1.06
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09.05 CS PS 24
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