SIGMA 150Ci - Manual (Page 38)

MAINTENANCE INSTRUCTIONS
4.8
Rotate the selector mechanism back to the OPERATE position and push in the lock slide to
ensure smooth operation and positive engagement. Attempt to push the lock slide towards
the SECURED position to test for a positive engagement of the lock slide. If a smooth
operation is not attained and/or the lock slide can be forced into the secured position by
testing for positive engagement, disassemble and thoroughly re-inspect for faulty
components. Thoroughly inspect all components for rough edges or burrs, etc. which could
cause jamming or irregular operation. Replace parts as necessary, re-lubricate and
reassemble the selector assembly. Repeat the functional safety testing to verify smooth and
safe operation of the selector mechanism. Do not install the serviced back plate
(lock mechanism) module to the exposure device at this point.
7 Remove the front plate containing the outlet port mechanism from the empty Model 880
device by removing the four 5 /
16
-18 x 1 1 /
2
in socket button-head screws using the
tamperproof tool bit mounted in a ratchet.
After removing the outlet port mechanism, clean the ‘S’ tube of the exposure device by
pushing cloth swabs wetted with solvent through the ‘S’ tube until they come out clean.
Use a dry cloth swab to remove any residual solvent from the ‘S’ tube after cleaning.
Clean the exterior of the Model 880 using a mild detergent solution to remove all dirt and
grime. Visually inspect the exposure device's stainless steel end plates for weld failures
(cracks, etc.) on the locking mechanism and outlet port ends. Ensure the handle, the bottom
contact surfaces and sides comprising the plastic jacket are intact. Check the bottom
surfaces of the jacket to ensure the contact area is not excessively worn allowing contact of
the stainless steel body with a flat work surface. Additionally, if dents to the device's body or
flanges due to accidental drops are found during this inspection, these repairs must be
performed at an AEA Technology QSA service center.
Ensure that all of the information contained on the Model 880 label is legible. The trefoil
and the warning, ‘Caution or Danger, Radioactive Material’, must be legible at a distance
of 3ft (approximately 1m). The model number, serial number and Type B certification
number must also be legible. For label replacement, remove the old label from the
exposure device by using a number 30 drill-bit mounted in a hand drill. Remove the rivet
heads used to fasten the label to the stainless steel body by drilling through the rivet head
just enough to allow the rivet head to rotate freely. Remove all rivet heads to remove label.
Install replacement label, install and use pop-rivet gun to seat new 1 /
8
in x 3 /
16
in stainless
steel rivets.
Disassemble the front plate (outlet port mechanism) by removing the set screw
(or roll pin) from the outlet port cover. Unscrew the two socket head cap screws from the
pivot disk. Remove and discard the two compression springs from the outlet port
mechanism and replace with new springs.
Clean all parts in solvent using a brush to dislodge all dust and dirt. Dry all components
thoroughly. Do not lubricate, leave all components completely dry.
Inspect for wear and burrs on the brass slider and rotor surfaces. Verify the tungsten port
shield is not loose within the rotor. If the port shield is loose, remove the set screw, apply
Vibratite™ thread sealant and retighten the set screw against the tungsten port shield.
If the port shield uses a roll pin, remove the roll pin and replace. Inspect the front plate's
outlet port for wear and burrs where the source guide tube bayonet fitting engages.