Constant Head Flow Controller - Emerson Rosemount MCL-220 Reference Manual

Maintenance
May 2019
16. Screw the membrane retainer in place.
17. Hold the sensor with the cathode end pointing down.
18. Give the sensor several sharp shakes to dislodge air bubbles trapped behind the
Table 8-1: Spare Parts
Part number
23750-00
9550094
33521-00
23501-09
23502-09
9210732
8.3

Constant head flow controller

8.3.1 General head flow controller information
After a period of time, deposits may accumulate in the constant head overflow chamber
and in the tubing leading to the flow cell(s). Deposits increase the resistance to flow and
cause the flow to gradually decrease. Loss of flow may ultimately have an impact on the
sensor performance.
The flow controller is designed to provide about 1.2 gal/hr (75 mL/min) flow. Loss of flow
to about 0.5 gal/hr (30 mL/min) causes about a 5% decrease in sensor output.
8.3.2 Cleaning the flow controller
The flow controller can be taken apart completely for cleaning.
Procedure
1. Use a strong flow of water to flush out the tubing.
2. To prevent leaks, apply a thin layer of silicone grease (or equivalent) to the two O-
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cathode.
The sensor may require several hours operating at the polarizing voltage to
equilibrate after the electolyte solution has been replaced.
Description
Electrolyte fill plug with wooden osmotic pressure relief port
O-ring, Viton 2-014
Membrane retainer
Monochloramine membrane assembly: includes one membrane
assembly and one O-ring
Monochloramine membrane kit: includes three membrane assemblies
and three O-rings
Monochloramine sensor fill solution, 4 oz (120 mL)
Use a pipe cleaner or small bottlebrush to remove more adherent deposits.
rings as the base of the overflow chamber and to the O-ring sealing the central
overflow tube to the base.
Reference Manual
00809-0100-3414
Emerson.com/Rosemount