Section 5: Maintenance; Replacing The Electrolyte Solution (Pn 9210391); Replacing The Capillary Disc (Pn 34142-00) - Emerson Rosemount 3200HP Instruction Manual

Instruction Manual
LIQ-MAN-3200HP

Section 5: Maintenance

5.1

Replacing the Electrolyte Solution (PN 9210391)

The reference electrolyte solution should last two to three months.
To replace the electrolyte solution:
1.
2.
3.
4.
5.
6.
7.
5.2

Replacing the Capillary Disc (PN 34142-00)

The reference capillary is protected by two filters, one on the inside of the disc and the other on the
sample side. During normal operation, suspended solids in the sample coat the filter and hinder
flow through the capillary. Occasionally, bacterial or fungal growth in the electrolyte solution will
coat the inside filter. Eventually, as the coating builds up, the electrolyte flow becomes too low and
the capillary disc must be replaced. The typical symptom of a blocked capillary disc is abnormally
low use of electrolyte (500 mL of electrolyte should last no more than two months) or pH readings
significantly lower (0.5 pH) than expected.
The capillary disc will also become blocked if the filters are allowed to dry out. Dried out filters
cannot be rehydrated. They must be replaced.
To replace a capillary disc:
1.
2.
3.
4.
5.
Maintenance
Remove the reservoir bottle from the clip on the back plate. Turn the bottle upright.
Unscrew the cap without disconnecting the filter or electrolyte tube. To avoid twisting the
electrolyte tube, turn the bottle, not the cap. To keep the cap and air inlet tube clean, hang
the cap from the reservoir clip using the electrolyte tube.
Discard any remaining fill solution.
Pour 500 mL of new reference fill solution (PN 9210391) into the reservoir.
Replace the cap. Remember to turn the bottle, not the cap.
Invert the bottle and reattach it to the clip.
Bleed air bubbles from the tube and sensor. Refer to step 11 in the
3200HP Sensor in Service (Section 2.3)
Lift the electrolyte reservoir out of the clip on the back plate. Turn the bottle upright and
disconnect the electrolyte tube from the filter. Place the shipping plug on the filter.
Disconnect the VP cable from the sensor and remove the sensor from the flow cell.
Hold the sensor in a horizontal position with the capillary disc pointing up. Use a small
screwdriver to gently pry the disc and O-ring out of the gland. Take care not to scratch the
gland. See Figure 5-1.
Remove the replacement capillary disc and O-ring from the container. Be careful not to
touch the white filter membrane portion of the disc with your fingers. Wear latex gloves if
necessary.
Place the sealing O-ring on the back side of the replacement capillary disc. See
Put the disc aside in a clean place. Keep the capillary disc wet. If the disc dries out it cannot
be rehydrated and must be replaced.
Maintenance
April 2017
Putting the Rosemount
Figure 5-1.
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