DAILY INSPECTION INSTRUCTIONS

Second, during termination of a radiographic exposure, the remote controls are used to retract the source back into the exposure device. When the source assembly is returned to the fully shielded position within the exposure device, the locking mechanism automatically secures the source assembly, preventing the source assembly from being inadvertently exposed from the fully shielded position. The automatic securing mechanism allows movement of the exposure device with the remote controls attached at the job site while preventing inadvertent exposure of the source assembly.

For the third feature, the controls cannot be removed from the exposure device locking mechanism unless the source assembly has been returned to the fully shielded position within the exposure device.

The complete radiography system consists of the radiographic exposure device containing the source assembly, the remote controls, source guide tubes and collimators (beam limiters) whenever possible.

The use of multiple source guide tubes must be a combined length shorter than the length of the remote controls, e.g. if the remote controls are 25ft (7.6m) long, only 3 source guide tubes can be utilized for a combined length of 21ft (6.4m). This consideration ensures the source assembly will be fully projected to the source stop (exposure head).

The source assembly must never be projected until the equipment is properly connected and all personnel have left the restricted area.

Transit mode

Rotating the handle of the remote control crank in the EXPOSE direction (counter-clockwise) moves the source assembly out of the shielded position in the exposure device and into the source guide tubes (projection sheaths). (See figure 3.3)

The source assembly is under positive mechanical control using the remote control crank. The remote controls that are fitted with an odometer to provide an indication of the sealed source’s position. The odometer reading should never be a substitute for the requirement and proper use of a radiation survey meter.

Source assembly

Sealed source

 

 

Control cable

Exposure device

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Remote

Locking

Shield

Outlet port

Source

control crank

mechanism

 

 

guide tubes

Figure 3.3 Sealed source in transit mode

3.4