Metek 920, Operator'S Manual With Essential Health And Safety Requirements

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5-42 | Model 920 Multi-Gas Analyzer
d. Disconnect and remove all other tubes from the Oven – including
any that run to connection points outside the Oven – that may
restrict the movement of the Heater Plate later in this procedure.
e. Remove the Aspirator/Sample Line Bracket (2 screws) from the
Heater Plate.
7. Remove the (2) M6 x 16 and (2) M6 x 40 screws that secure the Seal
Cover to the Seal Body (Figure 5-7.1).
Move the retaining ring from its groove in the Thermal Insulation
Tube to the space slightly above the groove (Figure 5-7.1) and remove
the Seal Cover.
Remove the Oven Plug (Figure 5-8).
8. Record the termination point of each wire connected to Terminal
Strips J1, J2 on the Heater Termination board (Figure 5-7.2) in the Seal
Body. Tag the wire(s) of RTDs and/or Heater Elements that will be re-
used with their termination points, to use when replacing them later.
Disconnect the faulty RTD and/or Heater Element wires from the
Heater Termination board.
9. Remove the (4) M6 x 35 screws and lock washers that secure the
Heater Plate to the Oven wall (Figure 5-8).
10. On the front of the Heater Plate, remove the (4) M6 x 25 screws that
secure the Upper Heater Plate to the Lower Heater Plate.
Slightly loosen the Seal Body gland nut (inside the Electronics
Enclosure).
Tilt the top of the Heater Plate toward you until you can access the (4)
M6 x 25 screws on the back of the Heater Plate. Tighten the Seal Body
gland nut to hold the Heater Plate in that position.
Remove the (4) M6 x 25 screws and carefully separate the Upper
Heater Plate from the Lower Heater Plate. Lean its top against the
Oven wall to expose the internal RTDs and Heater Elements. Take care
not to damage the internal wires.