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6.
Approach the exposure device observing the survey meter. You should not see a measurable radiation level
on the surface of the exposure device greater than the survey performed during the daily inspection. The
lock mechanism lock-slide will remain in the “exposed” (
RED
MARKING
) position when using the
Sentinel
TM
supplied pneumatic actuator. The sealed source assembly is automatically returned to the
shielded position by means of a steel spring that constantly pushes the source assembly into the shielded
position. The air actuator must overpower the steel spring tension to force the source assembly into the beam
port.
NOTE: The source assembly will not be automatically secured in the Model 989 by the lock-slide
mechanism. The lock-slide on the lock mechanism is intended to remain in the expose (
RED
MARKING
) position until all radiographic operations are completed. The source assembly is
maintained in the fully shielded position by the steel spring.
7.
The radiography crew can set up and perform radiographic operations. They must maintain direct
surveillance of the “High Radiation” area and control access to the “Restricted Area” which will be placed at
much shorter distances than conventional crank-out exposure devices.
C.
Disassembly of the Pneumatic Actuated system after use
1.
Survey the external surfaces of the device to assure that the radiation levels do not exceed 2 mSv/hr (200
mR/hr).
2.
Remove the air hose from the pneumatic actuator. Screw the manual push rod (part number TOL012) onto
the actuator rod, and pull the tool until the lock-slide trips and indicates the source assembly is secured
(
GREEN MARKING
).
Care must be taken while connecting the manual push rod to the actuator so that a force higher than 7
lbs is not applied during the connection. A force higher than 7 lbs can cause the source to move into a
non-fully shielded position.
Figure 22 – 989 with Lockslide in Open
Position and Retraction Rod Attached to
Actuator
Figure 23 –989 with Lockslide in the Secured
Position and Retraction Rod Attached to
Actuator
3.
Rotate the selector ring of the lock mechanism of the device from the “operate” position to the “connect”
position. This will release the safety plug collar assembly and pneumatic actuator from the lock mechanism.
Summary of Contents for 989
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