Spare Parts; Chlorine Sensor Parts - Emerson Rosemount Analytical FCLi Instruction Manual

MODEL FCLi

SPARE PARTS

33970-00 Fill Plug
33968-00 Membrane retainer cap
23501-10 pH-independent free chlorine membrane assembly, includes one membrane assembly and O-ring
23502-10 pH-independent free chlorine membrane assembly, includes three membrane assemblies and
O-rings
24146-00 pH-independent free chlorine sensor electrolyte kit, includes three bottles of saturated succinic acid
solution and three bottles of succinic acid crystals
7.2.4 Storage.
The sensor must be stored in a flowing sample. Minimum sample flow is 0.5 gph (30 mL/min). If the sensor
cannot be stored in a flowing sample...
1. Turn off power to the analyzer.
2. Remove the sensor from the flow cell.
3. Replace the membrane with the shipping membrane provided with the sensor. For a replacement shipping
membrane order PN 23501-00.
4. To protect the sensor from physical damage, store it in the dry flow cell.
7.2.5 Rejuvenating a chlorine sensor following improper storage.
If the sensor is stored in a stagnant sample for more than a day or two, it can become contaminated with copper.
Corrosion of the external copper electrode produces copper ions, which diffuse through the membrane into the
sensor. If the sensor was powered up during storage, copper will plate out on the cathode. If the sensor was not
powered up, the copper will start plating out as soon as the polarizing voltage is applied. Once copper has coat-
ed the cathode, the sensor zero current will become very high, and the sensor will be unusable until the cathode
has been cleaned.
1. If the sensor was not powered up during storage, DO NOT APPLY POWER. Empty the fill slurry and thoroughly
rinse the sensor with deionized water. Refill the sensor with fresh fill slurry. Let the sensor run in flowing chlori-
nated water overnight. Zero and calibrate the sensor. See the analyzer instruction manual for details. The zero cur-
rent should be less than about 100 nA.
2. If the sensor was powered up during storage, the cathode is probably coated with metallic copper. Disconnect
the sensor from the analyzer. Remove the membrane and clean out the fill slurry. Immerse the mesh cathode
in 10% nitric acid solution (10 mL of concentrated nitric acid in 90 mL of water) for about five minutes. Rinse thor-
oughly with deionized water. Refill the sensor with fresh slurry and install a new membrane. Let the sensor run
overnight in flowing chlorinated water. Zero and calibrate the sensor. The zero current should be less than about
100 nA.
48
fill plug
FIGURE 7-2. Chlorine Sensor Parts
o-ring
membrane
retainer cap
SECTION 7.0
MAINTENANCE
membrane
assembly