RKI Instruments EAGLE 2 Manual - Manual (Page 178)

168 • Maintenance EAGLE 2 Operator’s Manual
24. Make sure that the top case gasket is fully seated in its groove and
carefully put the top case back on the bottom case. If you have any
difficulty mating the top and bottom cases, inspect the placement of the
main PCB and the placement of the top case gasket.
25. Turn the EAGLE 2 upside down and tighten the three case screws to
secure the top case to the bottom case.
26. Calibrate the PID channel as described in “PID Calibration” on page 143.
Replacing the Electrode Stack
The electrode stack can last for the life of the PID sensor if the EAGLE 2 is
used in a very clean, controlled environment. When used in a heavily
contaminated or dirty environment, the electrode stack may only last a
month. A contaminated electrode stack will cause a drop in sensitivity which
can cause problems calibrating the PID channel. The electrode stack should
be replaced if the PID sensor shows signs of contamination even after
cleaning or replacing the lamp.
NOTE: Do not touch the new lamp window (the flat end) with your fingers
as this may contaminate the window with finger oil.
1. Verify that the EAGLE 2 is off.
2. Place the EAGLE 2 upside down on a flat surface or hold it upside down.
3. Unscrew the three case screws until they disengage from the top case.
They are captive screws so they will not fall off of the bottom case.
4. Turn the EAGLE 2 right side up and carefully lift the top case away from
the bottom case. Be careful not to lift it so far that it pulls on the main
PCB with the cable that connects the top case to the main PCB.
5. Lay the top case down next to the bottom case to allow access to the flow
system.
6. Locate the PID sensor adapter. It has a five wire cable and is normally
located next to the pump. The cable has a connector that mates to a PID
sub PCB that is installed on the main PCB. Figure 25 on page 137 shows
a PID sensor in a typical location.
7. Grasp the sensor adapter firmly and pull it out of the PID flow chamber.
Rock it back and forth gently if necessary to pull it out. Take care not to
pull the cable connector from the PID sub PCB.
8. The PID sensor protrudes from one end of the sensor adapter. Grasp the
PID sensor firmly and pull it out of the sensor adapter.
9. Place the PID sensor face down on a flat clean working surface.