- 18 -
Stored Position
Exposed Position
Figure 12 - PRINCIPLES OF OPERATION USING PART NUMBER ELE-027 PNEUMATIC ACTUATOR
B.
Principles of Operation - (crank-out) remote control
The Model 989 exposure device can be used with QSA Global, Inc. crank-out remote controls. The principals of
operation are similar to the use of the Model 880 series exposure devices equipped with automatic locking mechanisms.
During the performance of radiography, the radioactive sealed source assembly never leaves the exposure device. The
source assembly is projected from the stored position to a beam port within the exposure device using the remote
controls. When the source is returned to the shielded position, it is secured by the automatic locking mechanism. Source
guide tubes are not required when using the Model 989 exposure device with crank-out remote controls.
The Posilok (automatic locking mechanism) on the exposure device provides three main safety features for the
radiographer during radiographic operations.
•
First, the locking mechanism requires a deliberate action to enable exposure of the source assembly. This is
accomplished by coupling the control cable connector to the source assembly connector, coupling the remote
control connector to the exposure device locking mechanism and then pushing a lock slide from the SECURED
(
GREEN MARKING
) position into the EXPOSE (
RED MARKING
) position. The lock slide must be manually
pushed into the EXPOSE (
RED MARKING
) position prior to each radiographic exposure to enable operation of
the remote control.
•
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 from
being inadvertently exposed from the fully shielded position.
•
For the third safety feature, the controls cannot be removed from the exposure device locking mechanism unless
the source assembly has been returned to the fully shielded and secured position within the exposure device.
Summary of Contents for 989
Page 1: ...MAN 037 October 2017 ...