Heater/Thermocouple Replacement - Ametek Thermox WDG Insitu User Manual

Heater/Thermocouple Replacement

1.
2.
3.
4.
5.
1.
3.
4.
5.
6.
7-10 | Thermox Series 2000 WDG Insitu Analyzer
Disconnect power from the sensor and control unit and allow the sen-
sor to cool before replacing parts inside the sensor.
Remove the inner probe assembly and the cell.
Slide the heater and cell leads out of the inner probe assembly.
Mark the location of the spiders on the heater assembly with a magic
marker. They must be spaced the same way when you reattach the
spiders to the inner probe assembly. Loosen the set screws on all of the
spiders using a 1/16" socket head.
Remove the cell clips from the heater and then remove the heater
from the spiders.
Before discarding the old heater, transfer the marks from the old heat-
er to the new heater. Place the alignment spider, identified by four set
screws vs. only one set screw for other spiders, 10 inches from the tip
of the plasma-sprayed end (heater end). The other spiders are placed
every 12 inches thereafter.
Replacing the Heater
Slide the new heater through the spiders being careful to avoid con-
tact with the white coating on the heater against the spider. Figure 7-3.
Position the spiders on the heater using the marks made in Step 5 in
the previous section. Tighten the 1/16" set screws on the alignment
spider using a 1/16" allen head wrench so the heater wall doesn't
touch the spider wall. This is not required for the other spiders - just
tighten the one set screw for each of these spiders.
Slide the heater, cell clips, and cell leads into the inner probe assembly
so that the end of the heater is 2 inches inside the end of the inner
probe assembly (wrench flats end of the probe assembly).
Follow the steps in "Replacing the New Cell" section to reassemble the
cell. Be sure that the heater assembly is centered in the first spider (4
set screws).
Reinsert the probe assembly by reversing the steps described in the
"Inner Tube Assembly Removal" section of this chapter.