SIGMA projetor - Manual (Page 24)

DAILY INSPECTION INSTRUCTIONS
3.2
Figure 3.1 Source assembly and remote control cable connectors
2 Exposure Device
The source assembly is shown in the stored position in a titanium or ‘S’ tube at the center of the depleted
Uranium shield of the exposure device. (See figure 3.2)
A remote control unit is shown with its control cable connector coupled to the source assembly.
High density depleted Uranium shielding is used in the exposure device to provide good radiological
protection with minimal weight.
A shielded outlet port cover mechanism permits a secure attachment of source guide tubes (projection
sheaths) without an elevation of radiation levels. The outlet port mechanism will not allow the source
assembly to be projected outside of the exposure device unless a source guide tube has been properly
attached to the outlet port. A three-step connection is accomplished by completion of the following steps:
1
Pull and rotate the spring-loaded outlet port cover a quarter turn (from a 12 o’clock to a 3 o’clock
position) in a clockwise direction. This action moves the protective cover away from the outlet port to
permit attachment of a source guide tube.
2 A bayonet-style fitting of the source guide tube is inserted into the outlet port and rotated a quarter
turn (from a 12 o’clock position to a 9 o’clock position) counter-clockwise. A complete insertion and
counter-clockwise rotation of the source guide tube fitting releases the lock and an internal shielding
rotor of the outlet port.
3
Rotate the spring-loaded cover an additional 60 degrees (from a 3 o’clock position to a 5 o’clock
position) in a clockwise direction until it stops. This last movement moves the outlet port shield out of
position and aligns a pass-through opening on the rotor with the ‘S’ tube and outlet port while
simultaneously securing the source guide tube fitting to the outlet port.
The design permits attachment of the source guide tubes without an elevation of radiation intensity at the
outlet port, minimizing the radiation exposure to the radiographer’s hands. The sealed source assembly
cannot be exposed out of the exposure device unless a positive connection of the source guide to the
device has been accomplished.
The exposure device’s locking mechanism provides three main safety features for the radiographer
during radiographic operations.