Emerson Rosemount Oxymitter 4000 Instruction Manual page 134

Oxymitter 4000
9-18
3. If equipped with the optional ceramic diffusion assembly, remove and
discard the setscrews and remove the vee deflector (Figure 9-11). Use
spanner wrenches from the probe disassembly kit (Table 10-1 and
Figure 10-2), to turn the hub free from the retainer. Inspect the diffusion
element. If damaged, replace the element.
4. Loosen the four socket head cap screws from the cell and flange
assembly and remove the assembly and the corrugated seal. The cell
flange has a notch that may be used to gently pry the flange away from
the probe. Note that the contact pad inside of the probe will sometimes
fuse to the oxygen sensing cell. If the cell is fused to the contact pad,
push the cell assembly back into the probe (against spring pressure)
and quickly twist the cell assembly. The cell and contact pad should
separate. If the contact pad stays fused to the cell, a new contact/
thermocouple assembly must be installed. Disconnect the cell and the
thermocouple wires at the crimp connections and withdraw the cell with
the wires still attached.
5. For units with integral electronics, disconnect the entire electronics per
"Replace Entire Integral Electronics (with Housing)", steps 2 through 5.
6. Remove four screws (7, Figure 9-3) from the probe finned housing. The
probe and the probe head can now be separated.
7. If the contact assembly is damaged, replace the strut or the contact pad.
Instructions for replacing the contact pad are in the cell replacement kit.
8. Remove and discard the corrugated seal. Clean the mating faces of the
probe tube and retainer. Remove burrs and raised surfaces with a block
of wood and crocus cloth. Clean the threads on the retainer and hub.
9. Rub a small amount of anti-seize compound on both sides of the new
corrugated seal.
10. Assemble the cell and flange assembly, corrugated seal, and probe
tube. Make sure the calibration tube lines up with the calibration gas
passage in each component. Apply a small amount of anti-seize
compound to the screw threads and use the screws to secure assembly.
Torque to 35 in-lbs (4 N·m).
11. Install the entire electronics per "Replace Entire Integral Electronics
(with Housing)", steps 7 through 13.
12. Apply anti-seize compound to the threads of the cell assembly, hub, and
setscrews. Reinstall the hub on the cell assembly. Using pin spanner
wrenches, torque to 10 ft-lbs (14 N·m). If applicable, reinstall the vee
deflector, orienting apex toward gas flow. Secure with the setscrews and
anti-seize compound. Torque to 25 in-lbs (2.8 N·m).
13. On systems equipped with an abrasive shield, install the dust seal
gaskets, with joints 180°apart.
14. Reinstall the probe and gasket on the stack flange.
15. Follow the instructions in "Removal and Replacement of Probe" to
install the Oxymitter 4000 into the stack or duct. If there is an abrasive
shield in the stack, make sure the dust seal gaskets are in place as they
enter the 15°reducing cone.
16. Turn on power and monitor thermocouple output. It should stabilize at
29.3+0.2 mV. Set reference air flow at 1 l/min (2 scfh). After the
Oxymitter 4000 stabilizes, calibrate the unit. If new components have
been installed, repeat calibration after 24 hours of operation.
Instruction Manual
IM-106-340, Rev. 4.3
July 2017