7 Maintenance and Repair
Shields for Flange Mounting
40
44192BA2, Rev.03, 07/2021
7.4
Checking the Source Position and Shutter
NOTICE
Only close the shutter when all the sources are pulled back into the shield
and secured with the clamping screws!
If there are still sources in the measuring position, the steel rope is cut
through (sheared) off when closing the shield and the source falls into the
dip pipe.
The functional test of the shutter must be carried out by a person who is at least
an employee with general knowledge. We recommend conducting the test of the
shutter at the same intervals as the visual inspection if the operating condition of
the system allows.
1.
Ensure that no employees are present in the direction of the radiation beam
outlet. Otherwise, these persons will be exposed to the radiation beam when
the shutter is opened.
2.
Open and close the shutter several times (see chapter 6) while observing the
measuring signal of the corresponding measurement system.
The shutter works properly if the measured value approximately corresponds
to the maximum value when the shutter is closed (
CLOSED
position).
NOTICE
Only open the shutter when all sources are attached to the steel rope or
the flexible shaft and secured with clamping screws!
Unsecured sources fall into the dip pipe when the shield is opened.
Tip
Alternatively, you can measure the dose rate in the beam path. In this case,
the dose rate in the
CLOSED
position must be clearly lower than in the
OPEN
position. At the same time, the dose rate in the
CLOSED
position may not be
significantly higher than at other parts of the shield.
3.
Return the locking cylinder to its starting position (
OPEN
position or
CLOSED
position).
4.
If applicable, reinstall the fixing screws and/or the padlock.
5.
Immediately report any malfunction or stiffness of the shutter to the
competent radiation safety officer.
The functional test is completed.