SIGMA projetor User Manual
Page 34
MAINTENANCE INSTRUCTIONS
4.3
f. Check the locking mechanism and plunger lock to verify attachment and operation.
Grasp the entire mechanism with one hand and attempt to shift the mechanism. Retaining
screws that have been loosened from excessive vibration or improper maintenance will allow the
movement of the locking mechanism during this check. Loose screws must be tightened
according to the annual maintenance requirements prior to use or transport.
g. Use the Model 550 NO GO gauge to check for wear on the remote control cable connector and
the source assembly connector. Replace components that fail any of these tests.
h. Operationally check the locking mechanism and then the function of the entire system during the
first radiographic exposure of the work shift while within a restricted area.
Operation of the radiographic system verifies both the locking mechanism and entire system
operates smoothly and freely. If operation is faulty, remove the exposure device from service and
perform the complete annual maintenance.
Misconnect Test
After performing the quarterly maintenance, the complete radiography system must be tested by the
maintenance program administrator or Radiation Safety Officer. A misconnect test on the exposure
device including the radioactive source assembly and wind-out controls effectively tests the integrity of
the entire locking system. This procedure detects long-term wear (or damage) of the interrelated failsafe
system including identification of any excess wear on the control cable connector, device locking
mechanism and sealed source connectors simultaneously.
Note: Component wear occurs to both the control assemblies and the device lock assemblies
over time, therefore, to ensure acceptable equipment operation, the misconnect test must be
performed on each device lock assembly and control assembly combination that could be used in
the field. For example, if controls are used interchangeably with more than one specific exposure
device, then each control must be checked with each device to ensure the failsafe system for all
control assembly/device combinations are compliant.
WARNING
The test should only be performed by personnel that are formally trained, authorized and thoroughly
familiar with annual maintenance procedures. This test is performed by engaging the remote control
connecting plug assembly into the exposure device's locking mechanism WITHOUT first engaging the
control cable connector within the source assembly connector.
The ability to then rotate the locking mechanism from the CONNECT position towards the LOCK position
indicates critical dimensions of the locking system are excessively worn to an unsafe condition. Extreme
care should be exercised to prevent rotating the locking mechanism's selector ring beyond the
LOCK position (see WARNING above). If the locking mechanism and remote controls fail a misconnect
test the equipment must be removed from radiographic operations. The equipment must not be used until
repairs are performed and misconnect test results are satisfactory.
During the performance of the misconnect test there is a risk of losing control of the radioactive
source assembly if:
the components are excessively worn or damaged
the person performing the test intentionally or inadvertently rotates the selector ring from the
CONNECT position to the OPERATE position
the person performing the test intentionally or inadvertently pushes the lock slide into the EXPOSURE
mode.
Contact a QSA Global, Inc. service center if you have questions regarding the misconnect test.